You can use countif, for example:
=COUNTIF(A1:A20,"GS-4")
The second parameter is the criteria, you can use a cell reference instead,
to make the formula more flexible.

"dap1" wrote:

Want to total cells in which the text is 2 letters followed by a number
between 1 and 15. Example want to know how many GS-4 are in a given range of
cells.