Not really sure what to call it, but I work with a lot of taxation and there is a lot of "what if" in my work. One problem that I can't seem to get started on is as follows:

Employee has a $20,000.00 Cap.
Employee has uses $10,000.00 so far.
With each amount, there is a benefit called tax assistance applied. So in reality the employee may not get all the $10k remaining, but more so $7k as then $3k of tax assistance would be appied to make up the $10 total. But it's going to be based of other specifics such as their policy (4 of them). So I'm looking to put a formula in place that will give me the max amount they could be paid without going over after tax assistance is applied. I think I've done this in the past, but for the life of me I can't either remember or I am thinking of something else.