I don't know which version of Excel you're using, but if it's not 2007 you can always find out by simply using <End>,<Right>. Just go out to the far right of the existing data—<Ctrl-End> should get you there—then hit the <End> key, then hit the right arrow. (Don't hold <End> down like a <Shift> key; hit it and release, then hit <Right> and release.) That'll take you to the end of the worksheet, and you can then see for yourself which column is last in your version.