Concatenate multiple data ranges (defined columns)

I'm trying to get a drop down menu that will show the list of not just one defined data range, but many all stuck together. e.g "Name1" has the data "1,2,3" in it, and "name2" has data "4,5,6" in it. i want the drop down to show "1,2,3,4,5,6" in list form obviously. I'm using Excel 2007

not sure if Ive explained it well but i hope you understand.

If by drop-down menu, you mean a data validation drop-down, you can't; you need to create one contiguous range.

yeah i do, sorry i didn't mention that. thanks for the help, at least i wont be scrambling around now trying to find the answer.