How to set up a 3rd (non drive) motor in C++ Windriver

[Stonemotmot]

I'm relatively new to programming in C++ and i have a question regarding how to set up a third motor for say arm control. I am using the default Simple Robot Template in windriver. I already understand how to set up tank and arcade drive but as this 3rd motor will only be used for arm control and not driving I'm hesitant to reuse those commands. The biggest problem I am having right now is figuring out how to take a joystick input such as a get-Axis or something like that and send the information to a motor or speed controller. Thanks in advance.