A microcontroller can easily send the proper signals; check out NESBot for an example. Here's a video of NESBot playing the original NES Tetris with a series of inputs that manipulates the RNG: http://tasvideos.org/1502M.html .

You just need to emulate the game when planning out the series of moves, to figure out what timing to use to manipulate the RNG and get the pieces you want.