Basic syntax for multiple criteria sum is
Code:
=SUMPRODUCT((Range1=Criteria1)*(Range2=Criteria2),RangeToSum)
Note, Each range reference must be of equal size, and cannot be entire column refs like A:A. You must specify Row #s like A1:A100
so for example,
Code:
=SUMPRODUCT((A1:A100="ALPHA")*(B1:B100="TYPE1"),C1:C100)
you can replace "ALPHA" and "TYPE1" with Cell references containing those values.