circuitry is quite simple u need to attach RF Tx module(or the modeule which u using) to microcontroller and that micro controller to be interfaced with PC using RS232 in b/w u need a level converter max232/233
at the receiver end just connect your RX module to microcontroller and decode the data what you have send
for example i am send 0001 for forward from Tx
the at Rx end i need to make my microcontroller programme in such a logic that if i recieve 0001 then my machine should go to forward direction.