Hi,
as far as I know you have to push a button so C2 recognizes the gamepad and it has to be XBox compatible
you could check that
create a few textobjects and in the eventsheet
gamepad | On gamepad 0 Button A is pressed
subevent Gamepad | gamepads are supported | obj_textbox0 | set text to "0 is supported
same for gamepad 1, 2, 3
There is also a check "has gamepads" and "on gamepad connected"