Hi Jim
This solution requires an array formula, so it will take some time to calculate 3000 items.
Columns B:F show how the formula in column G is build.
With ideas from
http://www.excelformeln.de/formeln.html?welcher=101.
<table valign="middle" colspan="8" style="font-family: Calibri; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255); font-size: 11px; font-weight: normal; font-style: normal;" border="1" cellpadding="2" cellspacing="0"><colgroup><col width="28pt"><col width="95,25pt"><col width="60pt"><col width="60pt"><col width="60pt"><col width="78pt"><col width="93,75pt"><col width="93,75pt"></colgroup><tbody><tr style="background-color: rgb(250, 250, 250);"><td colspan="8" align="middle">Worksheet 'Tabelle1'</td></tr><tr style="background-color: rgb(202, 202, 202);"><td>
</td><td align="middle">A</td><td align="middle">B</td><td align="middle">C</td><td align="middle">D</td><td align="middle">E</td><td align="middle">F</td><td align="middle">G</td></tr><tr><td style="background-color: rgb(202, 202, 202);" align="middle">1</td><td align="left">1004Fort991</td><td align="left">991</td><td align="left">0991</td><td align="left">1004</td><td align="left">Fort0991</td><td align="left">1004Fort0991</td><td align="left">1004Fort0991</td></tr><tr><td style="background-color: rgb(202, 202, 202);" align="middle">2</td><td align="left">1004Fort993</td><td align="left">993</td><td align="left">0993</td><td align="left">1004</td><td align="left">Fort0993</td><td align="left">1004Fort0993</td><td align="left">1004Fort0993</td></tr><tr><td style="background-color: rgb(202, 202, 202);" align="middle">3</td><td align="left">1004Fort994</td><td align="left">994</td><td align="left">0994</td><td align="left">1004</td><td align="left">Fort0994</td><td align="left">1004Fort0994</td><td align="left">1004Fort0994</td></tr><tr><td style="background-color: rgb(202, 202, 202);" align="middle">4</td><td align="left">1004Fort995</td><td align="left">995</td><td align="left">0995</td><td align="left">1004</td><td align="left">Fort0995</td><td align="left">1004Fort0995</td><td align="left">1004Fort0995</td></tr><tr><td style="background-color: rgb(202, 202, 202);" align="middle">5</td><td align="left">1004Fort996</td><td align="left">996</td><td align="left">0996</td><td align="left">1004</td><td align="left">Fort0996</td><td align="left">1004Fort0996</td><td align="left">1004Fort0996</td></tr><tr><td style="background-color: rgb(202, 202, 202);" align="middle">6</td><td align="left">1004Fort997</td><td align="left">997</td><td align="left">0997</td><td align="left">1004</td><td align="left">Fort0997</td><td align="left">1004Fort0997</td><td align="left">1004Fort0997</td></tr><tr><td style="background-color: rgb(202, 202, 202);" align="middle">7</td><td align="left">1004Fort998</td><td align="left">998</td><td align="left">0998</td><td align="left">1004</td><td align="left">Fort0998</td><td align="left">1004Fort0998</td><td align="left">1004Fort0998</td></tr><tr><td style="background-color: rgb(202, 202, 202);" align="middle">8</td><td align="left">1004Fort999</td><td align="left">999</td><td align="left">0999</td><td align="left">1004</td><td align="left">Fort0999</td><td align="left">1004Fort0999</td><td align="left">1004Fort0999</td></tr><tr><td style="background-color: rgb(202, 202, 202);" align="middle">9</td><td align="left">1004FortGone</td><td align="left">
</td><td align="left">
</td><td align="left">1004</td><td align="left">FortGone</td><td align="left">1004FortGone</td><td align="left">1004FortGone</td></tr><tr><td style="background-color: rgb(202, 202, 202);" align="middle">10</td><td align="left">1105ForGlob1</td><td align="left">1</td><td align="left">0001</td><td align="left">1105</td><td align="left">ForGlob0001</td><td align="left">1105ForGlob0001</td><td align="left">1105ForGlob0001</td></tr><tr><td style="background-color: rgb(202, 202, 202);" align="middle">11</td><td align="left">1105ForGlob10</td><td align="left">10</td><td align="left">0010</td><td align="left">1105</td><td align="left">ForGlob0010</td><td align="left">1105ForGlob0010</td><td align="left">1105ForGlob0010</td></tr><tr><td style="background-color: rgb(202, 202, 202);" align="middle">12</td><td align="left">1105ForGlob100</td><td align="left">100</td><td align="left">0100</td><td align="left">1105</td><td align="left">ForGlob0100</td><td align="left">1105ForGlob0100</td><td align="left">1105ForGlob0100</td></tr><tr><td style="background-color: rgb(202, 202, 202);" align="middle">13</td><td align="left">1105ForGlob1000</td><td align="left">1000</td><td align="left">1000</td><td align="left">1105</td><td align="left">ForGlob1000</td><td align="left">1105ForGlob1000</td><td align="left">1105ForGlob1000</td></tr><tr><td style="background-color: rgb(202, 202, 202);" align="middle">14</td><td align="left">1105ForGlob1001</td><td align="left">1001</td><td align="left">1001</td><td align="left">1105</td><td align="left">ForGlob1001</td><td align="left">1105ForGlob1001</td><td align="left">1105ForGlob1001</td></tr><tr><td style="background-color: rgb(202, 202, 202);" align="middle">15</td><td align="left">1105ForGlob1002</td><td align="left">1002</td><td align="left">1002</td><td align="left">1105</td><td align="left">ForGlob1002</td><td align="left">1105ForGlob1002</td><td align="left">1105ForGlob1002</td></tr><tr><td style="background-color: rgb(202, 202, 202);" align="middle">16</td><td align="left">1105ForGlob1003</td><td align="left">1003</td><td align="left">1003</td><td align="left">1105</td><td align="left">ForGlob1003</td><td align="left">1105ForGlob1003</td><td align="left">1105ForGlob1003</td></tr><tr><td style="background-color: rgb(202, 202, 202);" align="middle">17</td><td align="left">1105ForGlob1003</td><td align="left">1003</td><td align="left">1003</td><td align="left">1105</td><td align="left">ForGlob1003</td><td align="left">1105ForGlob1003</td><td align="left">1105ForGlob1003</td></tr></tbody></table>
<table valign="middle" colspan="2" style="table-layout: auto; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255); font-family: Calibri; font-size: 10px;" border="3" cellpadding="2" cellspacing="0"><colgroup><col width="40pt"><col></colgroup><tbody><tr style="background-color: rgb(238, 170, 170);"><td>Cell</td><td>Formula</td></tr><tr><td>B1</td><td>
{=RIGHT(A1,COUNT(RIGHT(A1,COLUMN(1:1))*1))}</td></tr><tr><td>C1</td><td>
=TEXT(B1,"0000")</td></tr><tr><td>D1</td><td>
=LEFT(A1,4)</td></tr><tr><td>E1</td><td>
=SUBSTITUTE(MID(A1,5,9^9),B1,C1)</td></tr><tr><td>F1</td><td>
=D1&E1</td></tr><tr><td>G1</td><td>
{=LEFT(A1,4)&SUBSTITUTE(MID(A1,5,9^9),RIGHT(A1,COUNT(RIGHT(A1,COLUMN(1:1))*1)),TEXT(RIGHT(A1,COUNT(RIGHT(A1,COLUMN(1:1))*1)),"0000"))}</td></tr></tbody></table><table style="font-family: Arial; font-size: 8pt; background-color: rgb(255, 255, 255);"><tbody><tr><td style="font-weight: bold;">Contains array formula!
</td></tr><tr><td>Do
not enter the curly brackets {}.</td></tr><tr><td>Enter the formula with
CTRL-SHIFT-ENTER instead of just ENTER.</td></tr></tbody></table><table style="font-family: Arial; font-size: 7pt;"><tbody><tr><td style="color: rgb(51, 51, 51);">Created with Tab2HTML (v2.4.1). ©Gerd alias Bamberg</td></tr></tbody></table>