Hello Andres,

There are some rules for shortcut keys in AutoCAD:

"Valid modifier and key combinations include

- Function (Fn) keys containing no modifiers
- Number Pad (NUMPADn) keys containing no modifiers
- Ctrl+letter, Ctrl+number, Ctrl+function, Ctrl+virtual key
- Ctrl+Alt+letter, Ctrl+Alt+number, Ctrl+Alt+function, Ctrl+Alt+virtual key
- Ctrl+Shift+letter, Ctrl+Shift+number, Ctrl+Shift+function, Ctrl+Shift+virtual key
- Ctrl+Shift+Alt+letter, Ctrl+Shift+Alt+number, Ctrl+Shift+Alt+function, Ctrl+Shift+Alt+virtual key
Note: The virtual keys that are supported are Escape, Insert, Delete, Home, End, Page Up, Page Down, Left Arrow, Right Arrow, Up Arrow, and Down Arrow. The virtual key Escape can only be used by itself or with the modifier combination Ctrl+Shift+Alt."

So combinations like AQ, ZX and XC (and "`" key) - couldn't work as shortcuts, they only can be command aliases (which you can add and modify with CUI command in AutoCAD 2018):

The difference between shortcuts and command aliases is that in the case of shortcuts command activates immediately after you press it, and in case of command aliases you need to confirm it with pressing Return (Enter) or Spacebar key on the keyboard.

I think I can help you with function keys - F1? F2? etc. but I need to know exactly which AutoCAD version are you using.