Sure...
=SUMPRODUCT(($A$2:$A$5=1)*($C$1:$N$1="Qty")*($C$2:$N$5)) (in house)

the 1st part ($A$2:$A$5=1) tests to see if A contains 1
For those rows that have 1 in column A, it then checks to see if the heading is "QTY" ($C$1:$N$1="Qty")...this part is to make sure you dont start adding in numeric part numbers..., then adds the relevant values inthe range ($C$2:$N$5)

Hope that helps?