I had a busy weekend, so I apologize that I'm just now getting back to this. GameEx actually does have the ability to launch custom wrappers on a per game basis for Steam. Take a look at the GameEx\MEDIA\STEAM\WRAPPERS directory. Basically you would create a compiled script named according to the numeric Steam identifier of the associated game and place it in that directory. Then GameEx will auto-magically launch that script along side the associated game. AutoHotKey is by far the most popular choice for pulling this off, but really I suppose the script could be any executable, so long as it was named identically to the numeric identifier of the associated game. If you need help determining the numeric Steam identifier for a game, you can find it in the URL of the store page for said game. I'm blocked from reaching Steam at my current location, or I'd provide an example. Just take a look though, it's pretty easy to spot. The other thing you can do is take a look in the GameEx\MEDIA\STEAM\BOX directory, and find the banner for your game. The banner snap will also be named according to the Steam ID. Good luck man!