How to insert a minion Powershell variable into Salt Pillar or Mine?
You can only insert the return into the mine.

Just specify the cmd.run (or possibly cmd.script) in your mine_functions and you will get the whole return back.

If you want to have a script that sets up extra config on the minion, I would recommend writing a custom grain.

https://docs.saltstack.com/en/latest/topics/grains/#writing-grains