Have you tried using the Wii controller in HID-to-Vpad? I don't have a Classic Controller [Pro], so can't confirm this, but with luck it may Just Work. Does it show up in HID-Test? If so, you can create a config file to make it work. Else it might be possible to make it work with the Network Client, if you have a PC and a driver to make the Wiimote talk to it.