=SUMPRODUCT(--($I$2:$I$693="TXA"),--ISNUMBER($R$2:$R$693))

I would like to modify the second half of the formula so it counts all cells that match a specific date range using the following date format.

Ex: 4/8/2013 through 4/15/2013

Is this possible. If so how would I revise my formula?

Thank you

Tom