Is this the same project that someone posted about on Society of Robots?
In that post, the suggestion was to actually post a wiring diagram of all the parts. I also seem to remember that the request got a suggestion to use relays to replace the switches, or perhaps PWM motor controllers like a Sabretooth, and drive those relays or controller from an Arduino or similar small computer, and use an Xbee serial adapter, or WiFi "shield," to tell that Arduino what to do remotely.
Even if that wasn't you, well, that's what I would recommend for your case :-)