How to run regedit in proton?

[metro952]

Compatibility Report

• Name of the game with compatibility issues: Assassin's Creed II
  How do I do this in proton?
• Steam AppID of the game: 33230

System Information

• GPU: Radeon RX 6700
• Video driver version: mesa 24.2.8-1ubuntu1~24.04.1
• Kernel version: 6.8.0-59-generic
• Link to full system information report as Gist:
• Proton version: 9.04

I confirm:

• [ x] that I haven't found an existing compatibility report for this game.
• [ x] that I have checked whether there are updates for my system available.

Symptoms

I want to run the game in Polish, which according to this guide https://steamcommunity.com/sharedfiles/filedetails/?id=1382260075 is preloaded in the game only to be changed via regedit.
And how do I change the permissions as in tutorial point 7 to 12?

Reproduction

[s4midev]

WINEPREFIX="prefixpath" wine regedit

[metro952]

What should I put in this prefixpath?
What is it for the steam game?

And those permissions settings or for the key?
In wine I didn't see these but maybe in proton they are.

[NorfLoud]

Install the "protontricks" utility. Launch it, select your game, and go to its prefix settings, where it will be possible to run "regedit" for this prefix.