I am glad that you were able to get your VNH5019 working with your Arduino Uno. We do not have any code that allows someone to control motors with SparkFun’s Wireless Joystick Kit, a pair of XBees, and a VNH5019. You would have to write your own code to interpret the signals from the XBees and control your motors in the specific ways you want. However, if you have the VNH5019 shield, you should be able to get a good start on that by using the functions in our Arduino library for the shield. Those functions are documented on the GitHub page for that library.