Sumproduct with month and year ???

I have the following formula thats working, but I want to add the year argument also:

=SUMPRODUCT(--(MONTH('D:\Documents\Rise-N-Shine\Excel Documents\[Income & Expence Log.xls]expences'!$C$2:$C$9999)=1)*'D:\Documents\Rise-N-Shine\Excel Documents\[Income & Expence Log.xls]expences'!$N$2:$AX$9999)

Jan/2011

I tried adding year, but when I do it wants to multiply !$N$2:$AX$9999. What I'm looking for is sum !$N$2:$AX$9999 when =SUMPRODUCT(--(MONTH('D:\Documents\Rise-N-Shine\Excel Documents\[Income & Expence Log.xls]expences'!$C$2:$C$9999)=1)* is Jan/2011 like 1/12/11 or 1/13/11.

Either:

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or:

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I'd normally advocate the latter approach to reduce risk of coercion errors, however, in this instance given the different array dimensions necessitate explicit coercion of the summation range this point is a little moot.

Thank you verry much, the first one worked great!