Looking to force a game to use a specific controller,or other creative solutions

[Monsterclip]

This is sort of a weird one.

I have my new PC-based (Windows 10) cabinet running Guitar Hero 3 and GH:World Tour, the PC versions. I have a wireless 360 guitar connected to a Microsoft Wireless Receiver and it works flawlessly.
As soon as I plug in my Aimtrak gun (which works perfectly in MAME, Dolphin, etc.), the Guitar Hero games will launch and won't pick up the guitar. It just doesn't seem to register as the controller for the game. The keyboard is still functional and I can operate the game that way.
Now, the weird part is that even when the gun is plugged in the guitar still works fine in Dolphin to play Rock Band 3 or Beatles Rock Band. So I know it's not being disabled.

I've spent hours troubleshooting.
I've tried removing all other USB devices besides the guitar, guns and keyboard/mouse.  I've also tried the devices in different ports to troubleshoot any faulty ports.
Keyboard/mouse + guitar = guitar works perfect.
Keyboard/mouse + guitar + guns = guitar doesn't work in Guitar Hero 3 and World Tour, but works in Dolphin.

My best guess is that Guitar Hero is picking up the Aimtraks as the controller it wants to use and essentially locking out the guitar.
I've tried looking into GH settings to see if there's a way to set a controller in an .ini or some other settings file, but the only settings file I see for those games just saves my normal game settings like resolution.

I was wondering, is there a way to force an application/game to ignore a usb device or force it to use a specific device? That would be my next attempt at troubleshooting.

Also up for any other suggestions on solutions.
Some solutions I've already passed on:
- use joy2key or xpadder and map the working keyboard to the guitar. This is a last resort, since I really want the star power tilt functionality and the whammy bar, both which work perfectly in the no-gun scenario.
- unplug the guns before you use guitar hero! Not an option. Everything is cleanly inside the heavy cabinet which is against the wall.

Any wizards out there have any clues? Or maybe someone has experienced something like this before?

Thanks in advance.