scripting runas /netonly RSAT

Hello, I manage a few different tenants from a single workstation that obviously can’t be joined to every domain. I connect through a VPN and then typically use runas with a /netonly switch to run mmc/RSAT. I am trying to script this task as to avoid typing this tedious run line with every connection. I would like to leverage Get-credential to input domainuser and password but this is where I’ve hit a wall. I can’t figure out how to use powershell to accomplish what I want to do here in terms of /netonly authentication to a different domain. Any tips?