I am hoping that I am not the first person to have to do this, but I
can't find anything searching Google groups...

I have some financial models which mock a relational database. The
basic construction is data in tables and summary reports using
SUMPRODUCT referencing dynamic ranges in the tables.

I am now being asked to prove the formulas by generating another file
which calculates all the reports the "old-fashioned way".

Basically no one can audit my files because it is a "black-box"
solution.

Any ideas on how to prove or audit SUMPRODUCT without building a
completely separate, non-dynamic model to test if the result is the
same?

TIA!