I don't use excel that much, so no formula. Excel has a solver routine that lets you pick a formula cell and target cell which it will iterate to solve for the value. IIRC, it is part of the add-on package.
I heve 100% ,96.9% ,I need more strike ? What is the additional strike, so I can make Interpolation ?
I understand that I get to model Vanna-Volga, but with the other points?