Just a thought but would a inverse keylogger work?

I would guess something like this- an arduino hooked up to something you can operate (BigBuddy?). This could then ask you for your PIN code (2 taps, 3 taps, 2 taps)

Once arduino is happy it will quirt a pre-stored key sequence into the USB port, acting as a keyboard, and unlock what you need.

I have no idea if it is really viable but its the best I have.