I think I maybe barking up the the wrong tree...
I have problem that takes hours to optimize using solver.
(5 large data sets fit to 4 equations - using least squares.
I wrote a macro to determine the SS of the fit error ( in hopes of
speeding things up a bit.)
My target cell is a function that calls the error fitting subroutine.and
returns the SS error
I pass all the parameters (cells) I want to change through the macro so
it recalculates automatically

The macro works fine, the subroutine works.
When I use solver I get value# in the target cell.
I'm using Excel 2000 - is there a work around or am I trying to do
something that is outside of solvers capability?

Thanks in advance,
Gregg