- create a shortcut link on desktop for the specific game in epic launcher
- Go to the properties of this shortcut and copy the url For Tony Haw's Pro Skater 1+2 its: "com.epicgames.launcher://apps/Guppy?action=launch&silent=true"
- Go to steam and add a non steam game to your lib
- Search for '''cmd.exe'''
- Change the launch properties to /k start com.epicgames.launcher://apps/Guppy?action=launch^&silent=true & exit
- Change the name and icon if you will
- done
With these steps, it was possible to use the steam controller and overay in Tony Hawk's Pro Skater+ 1+2.
You can add "-com.epicgames.launcher://apps/gamesluggoeshere?action=launch&silent=true" to the launch options of the Epic Launcher shortcut in Steam and it will launch the game, just make sure that hyphen is in front of it. And of course don't forget to close the Epic Launcher when you're done so Steam doesn't think you're still in-game.