Use a Cronusmax Plus (set via the Cronus Pro software to be a PS3/PC input and PS3/PC output adapter) connected to a PS3 to PS2 Brook Superconverter connected to a PS2 to Gamecube controller adapter. One these are connected together you can connect the program port of your Cronusmax Plus to your PC and you can set it up for any controller plugged into your PC to go out into your system of adapters to ultimately be recognized as a Gamecube controller signal.