You could put a formula like this in C1:

=(A1=B1)*1

then copy down, which will give you a series of 1s and 0s, then in D1 you could have this formula:

=SUM(C:C)

to give you the count of identical records.

Or, if you want one formula, you can use this:

=SUMPRODUCT(--(A1:A100 = B1:B100))

adjust the 100 to suit how much data you have.

Hope this helps.

Pete