try this...(change m31:m33 to whatever range you'd like to cover)

=SUMPRODUCT(--(LEFT($M$31:$M$33,1)="I"),--(RIGHT($M$31:$M$33,LEN($M$31:$M$33)-1)))

"oops" wrote:

I need to pick certain cells from a calendar, and add the numbers in those
cells. The problem I am running into is that my data is entered in random
cells, and in following format: I8, I3, I5. I need to find all the cells with
data beginning with the "I", and then add the numbers in the cells. from
above examples, it would be 8+3+5 for a total of 16. I have been trying the
countif function, but no luck yet. Any Ideas?