using a cell's text as part of a filepath in another cell

[zest1]

can someone please tell me the proper syntax to use a cell reference for part of a file path in another cell? I can't seem to get it to work.

A2 = proj1

I'd like this:
C:\projects\["A2"&.xls]

[mdmackillop]

="C:\Projects\" & A2 & ".xls"

[zest1]

thanks