Have a list of sheet names in a column of yoru summary sheet. Let's say in
cells D1 to D50

=SUMPRODUCT(COUNTIF(INDIRECT("'"&D1:D50&"'!D24")," C"))

"Curtis" wrote:

Column D Row 254 contains the text "C" in all worksheets (which have
different numeric names..i.e. 1400 thru 1423)

In a summary sheet in the same workbook I need to count the number of
instances "C" occurs.

I will later use this formula to count it the value is "D" or "E"

Thanks