SUMPRODUCT with SUM nested, can it be done?

Hello,

I'm trying to write a sumproduct that sums a variable line of arrays based upon certain criteria; =SUMPRODUCT(--(AN3:AN6="L"),SUM(M3:AE6))

As you will see I am trying to SUM a different size array to the criteria array, and there am getting a #VALUE error.

My question is; is there a way of performing the SUM operation within the SUMPRODUCT formula? As the SUM array itself will change based upon other variables and I can't just create a matching column array with the SUM a standalone operation.

Any help would be greatly appreciated!

Thanks

rikkydik