This is not so much an error as a question about functionality.

I have a list in a worksheet, and one of the columns contains a number of entries. I'd like to filter out the duplicates and simply have a list with one of each entries.
For example, my list has codes entered that represent geographic locations. I'd like to get a list of all the geo codes that are in use in the list, so I can compare it to the master list and see which codes aren't in use right now. The list is so long that manually deleting the duplicate codes would take forever.

Can anyone help? I'm using Microsoft Office Excel 2003.

I’m not sure if this will help with your issue or not, but take a look here:
http://office.microsoft.com/en-us/excel/HA...=CL100570551033
Also if you scroll down to the bottom of the page, you’ll find some links that discuss something similar to your issue.