Excel Solver Run Function per Iteration

Hi.

I am running a non-linear optimization. Within this optimization I have to run functions/macros that update specific cell values that the optimizer has to use.

for Example:

Iteration 1 - solver changes cell A1 which is the cell that can be changed by the solver from 2 to 1             Due to that an intersection point changes its value which is calculated by a macro that has to be run. How can I do that? Then the solver is allowed to check and perform the next iterations.

Thanks

Dominik