Eeek! Lost a mates key to his Hi-lux, how do we replace it!?

[XCwillo]

So i borrowed his lux to do a quick run at lunch, and have misplaced it somewhere around my room... or the mess hall, or the 100 meters between my building and the mess :S
Its a 90's model lux, pretty old me thinks, just got a single little key, any ideas on what the go is for getting a new one? Do we have to go through toyota or can it be done by other parties??

Cheers
Willo