How to find the rental rate based on a NNN cap rate in EXCEL?

[Hunter Purnell]

I'm having trouble figuring out how to do this in excel. I want to see what the rental rate would be for a NNN lease based on the CAP rate. I have multiple % from 9% to 5% and want to see what rental rate would bring each CAP rate. For example 9% = (x - op. exp.) / PP x = rental rate. I'm not sure if I need goal seek or it can be done with an equation.