The cells in column A can be one of three options ... A,B, or C. I want to compare each cell to the one above it - if they match I want +1 in column B. If they don't I want -1 in column B. BUT I don't want any of the C's used for comparison. I want to skip all the C's and only compare the A's and B's (as if the C's aren't there at all). What I want to happen appears in this image:

EXCEL.jpg

Any help on this would be greatly appreciated.