I made a stupid mistake.

I was configuring MAME controls to my control panel I just finished so I can stuff it into the case I made, and finish it up.
I went into UI controls to change UI Select to a combo of buttons to make configuring all the buttons quicker and easier. It didn't read my button presses first time, and resulted in 'none' as the button. I then hit escape on accident, and have locked the UI Select button to...well nothing. Now I can't get back into change it...well cause there is no select button.
I went roaming around through config files and couldn't find anything. What do I have to edit? What config file do I just have to overwrite to get moving again?
Thanks alot! This final tuning of everything before I get into in the cabinet is insane! I'm loosing my mind.
(PS. I'm using Maximus Arcade if that helps. I bought it...so worth it.

)