I'd like to develop a function/macro to use that will allow me to
concatenate two or more cells based on the cells I select. As I scroll
down in my data, sometimes there are two cells that must be
concatenated, but sometimes it is three or more. In the end I am
hoping to come up with a simple way to highlight the cells and hit a
quick user-defined shortcut key to replace the top-most cell with the
concatenation of the cells I've selected. I'm using Excel 2007.

Can anyone help me figure this one out?

-Marshall