Custom List generations using a macro or VB

[VPB]

I have a list of data, just in column A of a worksheet, and will never exceed 875 rows. I know how to make a custom list with it, but am looking to create a button that when clicked selects the entire column, A2:A875, and makes a custom list with it. I am using this same list with Data validation on another sheet, and 875 rows is alot to go through on a drop down, but I also want to prevent errors as well and prevent erroneous data from being entered. I already use conditional formatting to notify on duplicate data entry.

Summary:
User presses button to run macro which generates custom list from Sheet 2 A2:A875
User changes to Sheet one and fills out row with customer data and when types in the Data validation cells it auto fills data as types based off custom list generated.

Sheet 2 where the data is pulled from column A:
<style type="text/css">
table.tableizer-table {border: 1px solid #CCC; font-family: Arial, Helvetica, sans-serif; font-size: 12px;} .tableizer-table td {padding: 4px; margin: 3px; border: 1px solid #ccc;}
.tableizer-table th {background-color: #104E8B; color: #FFF; font-weight: bold;}
</style>

<table class="tableizer-table">
<tr class="tableizer-firstrow"><th>Box Serial</th><th>Received Date</th><th>Install Date</th><th>Aging</th><th>On Truck</th></tr> <tr><td>M40710NEC191</td><td>8/18/2011</td><td>9/15/2011</td><td>0</td><td>0</td></tr> <tr><td>M10603TCM561</td><td>8/23/2011</td><td>9/15/2011</td><td>0</td><td>0</td></tr> <tr><td>M10620TCC304</td><td>8/25/2011</td><td>9/15/2011</td><td>0</td><td>0</td></tr> <tr><td>TM4116912821</td><td>8/25/2011</td><td>9/15/2011</td><td>0</td><td>0</td></tr> <tr><td>TM4116914759</td><td>8/25/2011</td><td>9/15/2011</td><td>0</td><td>0</td></tr> <tr><td>M10532TDN316</td><td>8/26/2011</td><td>9/15/2011</td><td>0</td><td>0</td></tr> <tr><td>203643711</td><td>8/26/2011</td><td>9/15/2011</td><td>0</td><td>0</td></tr> <tr><td>222352572</td><td>8/26/2011</td><td>9/15/2011</td><td>0</td><td>0</td></tr> <tr><td>874809102442</td><td>8/26/2011</td><td>9/15/2011</td><td>0</td><td>0</td></tr> <tr><td>888933403257</td><td>8/26/2011</td><td>9/15/2011</td><td>0</td><td>0</td></tr> <tr><td>895019303152</td><td>8/26/2011</td><td>9/15/2011</td><td>0</td><td>0</td></tr></table>

Sheet 1 where I already have drop downs with data validation and conditional formatting for highlighting duplicate values.

<style type="text/css">
table.tableizer-table {border: 1px solid #CCC; font-family: Arial, Helvetica, sans-serif; font-size: 12px;} .tableizer-table td {padding: 4px; margin: 3px; border: 1px solid #ccc;}
.tableizer-table th {background-color: #104E8B; color: #FFF; font-weight: bold;}
</style>

<table class="tableizer-table">
<tr class="tableizer-firstrow"><th>Box 1</th><th>Box 2</th><th>Box 3</th><th>Box 4</th><th>Box 5</th><th>Box 6</th><th>Box 7</th><th>Box 8</th><th>Box 9</th><th>Box 10</th></tr> <tr><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td></tr> <tr><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td></tr> <tr><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td></tr> <tr><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td></tr> <tr><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td></tr> <tr><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td> </td><td></td></tr></table>

Hope this is as clear as mud in what I am looking for, and Thanks in advance for excusing my ignorance if the answer is already clearly posted somewhere.