Referencing a cell outside the table in a structure formula

[sccole]

The following formula sums rows in a table from Jan (January) up to Dec (December). However, I want to make the second sum term, Mar (March), variable, and refer to a value outside of the table. How do I do this?

=SUM([@Name],Table3[@[Jan]:[Mar]])


<table border="0" cellpadding="0" cellspacing="0" width="464"><col style="mso-width-source:userset;mso-width-alt:3547;width:73pt" width="97"> <col style="mso-width-source:userset;mso-width-alt:2889;width:59pt" width="79"> <col style="mso-width-source:userset;mso-width-alt:2633; width:54pt" span="4" width="72"> <tbody><tr style="height:12.75pt" height="17"> <td style="height:12.75pt;width:73pt;font-size:10.0pt; color:black;font-weight:700;text-decoration:none;text-underline-style:none; text-line-through:none;font-family:Arial;border-top:.5pt solid black; border-right:none;border-bottom:.5pt solid black;border-left:none" height="17" width="97">Name</td> <td class="xl74" style="width:59pt;font-size:10.0pt;color:black; font-weight:700;text-decoration:none;text-underline-style:none;text-line-through: none;font-family:Arial;border-top:.5pt solid black;border-right:none; border-bottom:.5pt solid black;border-left:none" width="79"> Jan </td> <td class="xl74" style="width:54pt;font-size:10.0pt;color:black; font-weight:700;text-decoration:none;text-underline-style:none;text-line-through: none;font-family:Arial;border-top:.5pt solid black;border-right:none; border-bottom:.5pt solid black;border-left:none" width="72"> Feb </td> <td class="xl74" style="width:54pt;font-size:10.0pt;color:black; font-weight:700;text-decoration:none;text-underline-style:none;text-line-through: none;font-family:Arial;border-top:.5pt solid black;border-right:none; border-bottom:.5pt solid black;border-left:none" width="72"> Mar </td> <td class="xl74" style="width:54pt;font-size:10.0pt;color:black; font-weight:700;text-decoration:none;text-underline-style:none;text-line-through: none;font-family:Arial;border-top:.5pt solid black;border-right:none; border-bottom:.5pt solid black;border-left:none" width="72"> Apr </td> <td class="xl74" style="width:54pt;font-size:10.0pt;color:black; font-weight:700;text-decoration:none;text-underline-style:none;text-line-through: none;font-family:Arial;border-top:.5pt solid black;border-right:none; border-bottom:.5pt solid black;border-left:none" width="72"> May </td> </tr> <tr style="height:12.75pt" height="17"> <td class="xl70" style="height:12.75pt;font-size:10.0pt;color:black; font-weight:400;text-decoration:none;text-underline-style:none;text-line-through: none;font-family:Arial;border:.5pt solid windowtext;background:#D9D9D9; mso-pattern:#D9D9D9 none" height="17">Name 1</td> <td class="xl68" style="border-left:none;font-size:10.0pt;color:black; font-weight:400;text-decoration:none;text-underline-style:none;text-line-through: none;font-family:Arial;border:.5pt solid windowtext;background:#D9D9D9; mso-pattern:#D9D9D9 none"> 231,000 </td> <td class="xl68" style="border-left:none;font-size:10.0pt;color:black; font-weight:400;text-decoration:none;text-underline-style:none;text-line-through: none;font-family:Arial;border:.5pt solid windowtext;background:#D9D9D9; mso-pattern:#D9D9D9 none"> 254,100 </td> <td class="xl68" style="border-left:none;font-size:10.0pt;color:black; font-weight:400;text-decoration:none;text-underline-style:none;text-line-through: none;font-family:Arial;border:.5pt solid windowtext;background:#D9D9D9; mso-pattern:#D9D9D9 none"> 284,900 </td> <td class="xl68" style="border-left:none;font-size:10.0pt;color:black; font-weight:400;text-decoration:none;text-underline-style:none;text-line-through: none;font-family:Arial;border:.5pt solid windowtext;background:#D9D9D9; mso-pattern:#D9D9D9 none"> 252,000 </td> <td class="xl68" style="border-left:none;font-size:10.0pt;color:black; font-weight:400;text-decoration:none;text-underline-style:none;text-line-through: none;font-family:Arial;border:.5pt solid windowtext;background:#D9D9D9; mso-pattern:#D9D9D9 none"> 277,200 </td> </tr> <tr style="height:12.75pt" height="17"> <td class="xl70" style="height:12.75pt;border-top:none;font-size: 10.0pt;color:black;font-weight:400;text-decoration:none;text-underline-style: none;text-line-through:none;font-family:Arial;border:.5pt solid windowtext" height="17">Name 2</td> <td class="xl68" style="border-top:none;border-left:none;font-size:10.0pt; color:black;font-weight:400;text-decoration:none;text-underline-style:none; text-line-through:none;font-family:Arial;border:.5pt solid windowtext"> 231,000 </td> <td class="xl68" style="border-top:none;border-left:none;font-size:10.0pt; color:black;font-weight:400;text-decoration:none;text-underline-style:none; text-line-through:none;font-family:Arial;border:.5pt solid windowtext"> 254,100 </td> <td class="xl68" style="border-top:none;border-left:none;font-size:10.0pt; color:black;font-weight:400;text-decoration:none;text-underline-style:none; text-line-through:none;font-family:Arial;border:.5pt solid windowtext"> 284,900 </td> <td class="xl68" style="border-top:none;border-left:none;font-size:10.0pt; color:black;font-weight:400;text-decoration:none;text-underline-style:none; text-line-through:none;font-family:Arial;border:.5pt solid windowtext"> 252,000 </td> <td class="xl68" style="border-top:none;border-left:none;font-size:10.0pt; color:black;font-weight:400;text-decoration:none;text-underline-style:none; text-line-through:none;font-family:Arial;border:.5pt solid windowtext"> 277,200 </td> </tr> <tr style="height:12.75pt" height="17"> <td class="xl70" style="height:12.75pt;border-top:none;font-size: 10.0pt;color:black;font-weight:400;text-decoration:none;text-underline-style: none;text-line-through:none;font-family:Arial;border:.5pt solid windowtext; background:#D9D9D9;mso-pattern:#D9D9D9 none" height="17">Name 3</td> <td class="xl68" style="border-top:none;border-left:none;font-size:10.0pt; color:black;font-weight:400;text-decoration:none;text-underline-style:none; text-line-through:none;font-family:Arial;border:.5pt solid windowtext; background:#D9D9D9;mso-pattern:#D9D9D9 none"> 462,000 </td> <td class="xl68" style="border-top:none;border-left:none;font-size:10.0pt; color:black;font-weight:400;text-decoration:none;text-underline-style:none; text-line-through:none;font-family:Arial;border:.5pt solid windowtext; background:#D9D9D9;mso-pattern:#D9D9D9 none"> 508,200 </td> <td class="xl68" style="border-top:none;border-left:none;font-size:10.0pt; color:black;font-weight:400;text-decoration:none;text-underline-style:none; text-line-through:none;font-family:Arial;border:.5pt solid windowtext; background:#D9D9D9;mso-pattern:#D9D9D9 none"> 569,800 </td> <td class="xl68" style="border-top:none;border-left:none;font-size:10.0pt; color:black;font-weight:400;text-decoration:none;text-underline-style:none; text-line-through:none;font-family:Arial;border:.5pt solid windowtext; background:#D9D9D9;mso-pattern:#D9D9D9 none"> 504,000 </td> <td class="xl68" style="border-top:none;border-left:none;font-size:10.0pt; color:black;font-weight:400;text-decoration:none;text-underline-style:none; text-line-through:none;font-family:Arial;border:.5pt solid windowtext; background:#D9D9D9;mso-pattern:#D9D9D9 none"> 554,400 </td> </tr> </tbody></table>
Thanks