At the moment I can only think of one way to do it, but it's extremely tedious and rather dodgy. But if you still want to try it, here's what I am thinking.
Make global variable for all your control keys 'X', 'Y', etc. Make it a number variable or a text value, it's up to you (text would be easier but more tedious to type).
Set up your events so it's like if gamepad button A pressed set 'X' (the global variable) to "pressed", and then copy it and invert it and make it set 'X' to "released". This means that when Gamepad button A is not pressed it sets 'X' to "released".
This can be applied for the other actions too.
Then, make an event:
If 'X' = "released" --> (Your actions, don't shoot for example)
If 'X' = "pressed" --> (Your actions, Shoot for example)
That's a very clunky work around, but it should do it's job (I'm away from my PC so I can't really check).