Rule 75 prohibits anything but the dashboard from sending driver/operator input to the robot.
Personally, I think this rule should be waived assuming you demonstrate that control is turned off during the disabled period (you could do this and not tell them by having the cRIO try to connect back to the PC, or vice versa, and sending it commands that way. You won't have a nice wrapper, though, but joystick drivers will give you the values you already expect from, say, the Joystick class).
There is, however, virtual joystick software, so you can wire up a numpad or keyboard to something:
http://headsoft.com.au/index.php?category=vjoy