ronettes,

In whichever sheet you want to show the answer (which I assume is not 'F10 - Operations'), put the month name in B3, and this in whichever cell you want to show the answer:

=COUNTIFS(INDIRECT("'"& B3 & "'!" & "E:E");'F10 - Operations'!L19;INDIRECT("'"& B3 & "'!" & "BA:BA");1)

Ochimus