You could use an array formula like:
=SUM(IF(LEFT(A:A,1)="W",1))
Ideally, though, you'd restrict the range to less than an entire row or column (e.g. instead of A:A you might use A1:A100).

Array formulae are inserted with Ctrl-Shift-Enter.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]