So you want to generate a unique, ordered list of the numerical values in your column? try:
<b>Excel 2002</b><table cellpadding="2.5px" rules="all" style=";background-color: #FFFFFF;border: 1px solid;border-collapse: collapse; border-color: #A6AAB6"><colgroup><col width="25px" style="background-color: #E0E0F0" /><col /><col /><col /></colgroup><thead><tr style=" background-color: #E0E0F0;text-align: center;color: #161120"><th></th><th>A</th><th>B</th><th>C</th></tr></thead><tbody><tr ><td style="color: #161120;text-align: center;">1</td><td style="text-align: right;;">1</td><td style="text-align: right;;"></td><td style=";">Unique</td></tr><tr ><td style="color: #161120;text-align: center;">2</td><td style="text-align: right;;">1</td><td style="text-align: right;;"></td><td style="text-align: right;;">1</td></tr><tr ><td style="color: #161120;text-align: center;">3</td><td style="text-align: right;;">1</td><td style="text-align: right;;"></td><td style="text-align: right;;">2</td></tr><tr ><td style="color: #161120;text-align: center;">4</td><td style="text-align: right;;">1</td><td style="text-align: right;;"></td><td style="text-align: right;;">3</td></tr><tr ><td style="color: #161120;text-align: center;">5</td><td style="text-align: right;;">1</td><td style="text-align: right;;"></td><td style="text-align: right;;">4</td></tr><tr ><td style="color: #161120;text-align: center;">6</td><td style="text-align: right;;">2</td><td style="text-align: right;;"></td><td style="text-align: right;;">99</td></tr><tr ><td style="color: #161120;text-align: center;">7</td><td style="text-align: right;;">2</td><td style="text-align: right;;"></td><td style="text-align: right;;">#N/A</td></tr><tr ><td style="color: #161120;text-align: center;">8</td><td style="text-align: right;;">2</td><td style="text-align: right;;"></td><td style="text-align: right;;">#N/A</td></tr><tr ><td style="color: #161120;text-align: center;">9</td><td style="text-align: right;;">2</td><td style="text-align: right;;"></td><td style="text-align: right;;">#N/A</td></tr><tr ><td style="color: #161120;text-align: center;">10</td><td style="text-align: right;;">2</td><td style="text-align: right;;"></td><td style="text-align: right;;">#N/A</td></tr><tr ><td style="color: #161120;text-align: center;">11</td><td style="text-align: right;;">2</td><td style="text-align: right;;"></td><td style="text-align: right;;">#N/A</td></tr><tr ><td style="color: #161120;text-align: center;">12</td><td style="text-align: right;;">2</td><td style="text-align: right;;"></td><td style="text-align: right;;">#N/A</td></tr><tr ><td style="color: #161120;text-align: center;">13</td><td style="text-align: right;;">2</td><td style="text-align: right;;"></td><td style="text-align: right;;"></td></tr><tr ><td style="color: #161120;text-align: center;">14</td><td style="text-align: right;;">2</td><td style="text-align: right;;"></td><td style="text-align: right;;"></td></tr><tr ><td style="color: #161120;text-align: center;">15</td><td style="text-align: right;;">3</td><td style="text-align: right;;"></td><td style="text-align: right;;"></td></tr><tr ><td style="color: #161120;text-align: center;">16</td><td style="text-align: right;;">3</td><td style="text-align: right;;"></td><td style="text-align: right;;"></td></tr><tr ><td style="color: #161120;text-align: center;">17</td><td style="text-align: right;;">3</td><td style="text-align: right;;"></td><td style="text-align: right;;"></td></tr><tr ><td style="color: #161120;text-align: center;">18</td><td style="text-align: right;;">3</td><td style="text-align: right;;"></td><td style="text-align: right;;"></td></tr><tr ><td style="color: #161120;text-align: center;">19</td><td style="text-align: right;;">3</td><td style="text-align: right;;"></td><td style="text-align: right;;"></td></tr><tr ><td style="color: #161120;text-align: center;">20</td><td style="text-align: right;;">3</td><td style="text-align: right;;"></td><td style="text-align: right;;"></td></tr><tr ><td style="color: #161120;text-align: center;">21</td><td style="text-align: right;;">3</td><td style="text-align: right;;"></td><td style="text-align: right;;"></td></tr><tr ><td style="color: #161120;text-align: center;">22</td><td style="text-align: right;;">4</td><td style="text-align: right;;"></td><td style="text-align: right;;"></td></tr><tr ><td style="color: #161120;text-align: center;">23</td><td style="text-align: right;;">4</td><td style="text-align: right;;"></td><td style="text-align: right;;"></td></tr><tr ><td style="color: #161120;text-align: center;">24</td><td style="text-align: right;;">4</td><td style="text-align: right;;"></td><td style="text-align: right;;"></td></tr><tr ><td style="color: #161120;text-align: center;">25</td><td style="text-align: right;;">4</td><td style="text-align: right;;"></td><td style="text-align: right;;"></td></tr><tr ><td style="color: #161120;text-align: center;">26</td><td style="text-align: right;;">4</td><td style="text-align: right;;"></td><td style="text-align: right;;"></td></tr><tr ><td style="color: #161120;text-align: center;">27</td><td style="text-align: right;;">99</td><td style="text-align: right;;"></td><td style="text-align: right;;"></td></tr><tr ><td style="color: #161120;text-align: center;">28</td><td style="text-align: right;;">99</td><td style="text-align: right;;"></td><td style="text-align: right;;"></td></tr><tr ><td style="color: #161120;text-align: center;">29</td><td style="text-align: right;;">99</td><td style="text-align: right;;"></td><td style="text-align: right;;"></td></tr><tr ><td style="color: #161120;text-align: center;">30</td><td style="text-align: right;;">99</td><td style="text-align: right;;"></td><td style="text-align: right;;"></td></tr><tr ><td style="color: #161120;text-align: center;">31</td><td style="text-align: right;;">99</td><td style="text-align: right;;"></td><td style="text-align: right;;"></td></tr></tbody></table><p style="width:4.2em;font-weight:bold;margin:0;padding:0.2em 0.6em 0.2em 0.5em;border: 1px solid #A6AAB6;border-top:none;text-align: center;background-color: #E0E0F0;color: #161120">Sheet12</p><br /><br /><table width="85%" cellpadding="2.5px" rules="all" style=";border: 2px solid black;border-collapse:collapse;padding: 0.4em;background-color: #FFFFFF" ><tr><td style="padding:6px" ><b>Array Formulas</b><table cellpadding="2.5px" width="100%" rules="all" style="border: 1px solid;text-align:center;background-color: #FFFFFF;border-collapse: collapse; border-color: #A6AAB6"><thead><tr style=" background-color: #E0E0F0;color: #161120"><th width="10px">Cell</th><th style="text-align:left;padding-left:5px;">Formula</th></tr></thead><tbody><tr><th width="10px" style=" background-color: #E0E0F0;color: #161120">C2</th><td style="text-align:left">{=INDEX(<font color="Blue">$A$1:$A$31,MATCH(<font color="Red">0,COUNTIF(<font color="Green">$A$1:$A31,"<"&$A$1:$A$31</font>)-SUM(<font color="Green">COUNTIF(<font color="Purple">$A$1:$A$31,$C$1:$C1</font>)</font>),0</font>)</font>)}</td></tr></tbody></table><b>Entered with Ctrl+Shift+Enter.</b> If entered correctly, Excel will surround with curly braces {}.
<b>Note: Do not try and enter the {} manually yourself</b></td></tr></table><br />