As far as I have seen, the computer's choice seems predefined, not random at all. The only way to force the computer to do something else the next time (if you save and reload) is to use the same as the computer would have done, as m3m3c1s said, the computer will never use the same choice you do. I have also won by using the same choice 4 times in a row sometimes, so there is no logic based on what I as a player choose to use.
