Generate Letter Suffixes in Excel from AA to ZZ

If you need to generate a long list of letter suffixes in Excel and your sequence runs past Z, you can use this formula to generate double letter groups - AA, AB, AC, and so on.

=CHAR(65+TRUNC((C2-1)/26)) & CHAR(65+MOD(C2-1,26))

It will need to reference a corresponding number range in a helper column. AA begins at 1, not 27 as you might except. Thanks for Mike Milette for the idea posted here.