OpenGL is only used for the graphics, has nothing to do with inputs or the keyboard. I would recommend getting a USB gamepad, you can pick them up for about $10 and they work really great. This is the kind that we have been using:
p220
1. I can't set keys: INSERT, HOME PAGE UP, DELETE, END, PAGE DOWN, keys when numlock is on and-> [ ] ; ' , . /
When I play 1/1 this defect make hard to play.
2. When I play 1/1 me and my friend can't hold more then 3-4 keys at the same time.
common keyboard are really cheap, you can't press many button at the same time, try to find a joypad, or a very old heavy keyboard (these rare ones still working with all the key pressed)
I have old keyboard, that's not a problem. I think this depends on OGL :/ I know something about programme, and I think in DirectX will be no problem for that. OpenGL work with standard Windows API and that is a problem I think.