Resurrection of a dead thread. I have the solution for you as I was trying to solve the same problem.
One user posted a link to how to brew. This is actually correct but you have to manipulate the infusion formula and solve for Tw.
Wa = your sparge water volume in quarts
Wm = total strike water - volume of wort collected in quarts
I made myself a calculator to use with excel. I’d be happy to share if anyone is interested.