[Alan Anderson]

I think you need to be a little more detailed about exactly what you want. Do you want one motor to move "forward" as long as a button is pressed, and stop when you release the button? Do you want one button to start the motor going "forward", and another to start it going "backward", with the motor continuing to run while the buttons are released? Do you want a button on the second joystick to act exactly the same way as one of the buttons on the first joystick?

Controlling motors using joystick buttons is pretty simple, as long as you can define what it is that should happen each time a button is pressed or released.