WorksheetFunction.SumProduct (Excel)
Multiplies corresponding components in the given arrays, and returns the sum of those products.
The array arguments must have the same dimensions. If they do not, SumProduct returns the #VALUE! error value. SumProduct treats array entries that are not numeric as if they were zeros.
SumProduct (Arg1, Arg2, ..., Arg30)
Dim dblSumProduct As Double
dblSumProduct = WorksheetFunction.SumProduct(Arg1:=)