Possibility 1:

Repeat the calculation using a set of cell pairs, one pair for each round of iteration

Guess 1 Result 1

Guess 2 Result 2 (Guess 2 depends on Result 1)

Guess 3 Result 3 (Guess 3 depends on Result 2)

Possibility 2:

Perform the iterative calculation in .Net, then report the results back to the spreadsheet

Possibility 3:

Rewrite the Excel formulas so they don't need iteration. This is not always possible, but there are some awfully clever people active in the Excel Zone.

Possibility 4:

Use a Data Table to vary the guess, repeat the calculations, and report the result. Your answer won't converge completely, but you can get pretty close. I don't know if TMS Flexcel Studio supports this approach--but Excel certainly does.

Possibility 5:

Use Solver (or Goal Seek) to force the convergence. Once again, I don't know if TMS Flexcel Studio supports this approach--but Excel certainly does.

Brad