Excel>Tools>Goal Seek Equivalent?

I looking for an action in Numbers that would act like excel's "goal seek", where you select a result cell, designate a seek value, and then select a "change" cell, push go and get a nice quick iteration.

Example, you have a complex equation that pulls input from several cells and displays an answer in a single cell. With Goal Seek in Excel, I would designate the "Results" cell, enter the answer I'm seeking, then designate one of the cells that drive the equation, and press go. Excel would quickly give the "x" that produces "y" in my complex equation. An iterative equation solver.

Can't find one in version 08, maybe version 09?

Any clues appreciated,