joystick control of robot through wifi (NOT XBee)

I am trying to implement a joystick through wifi, to control my rover robot which is already communicating through a serial port wirelessly. I want to use another wifi shield and arduino to send the analog input of the joystick to the rover. Any help/suggestions? I have been trying to find other projects that have got this to work and only found one so far, but he used ps3 controller. I am wanting to use my on joystick.