Can Sheet1!A1:A8000 be used as variable in formula?

[pninja005]

I'm using a SUMPRODUCT function formula.

I would like to specify the arrays in different cells on my page.

eg:
C1 contains Sheet1!A1:A8000
C2 contains Sheet1!B1:B8000
C3 contains 4

and then use in the formula
=SUMPRODUCT(($C1=C3)*($C2=C3), etc..)

How can this be done ?

THx!

[pninja005]

Anyone ?

Thank you