Your question is not entirely clear, but it basically sounds like you want to control a stepper motor from our VNH5019 shield. Since this question is different from the topic you were posting in, I separated your post as its own topic.
In general, it will be easier to control a stepper motor from a dedicated stepper motor driver, since those devices have the ability to limit current to the coils. If you do not already have a VNH5019 shield, you might take a look at our stepper motor drivers.
However, it is possible to use that shield to drive a stepper motor. We have some example code for doing so in this post. Please note that this code is for the MC33926, but works the VNH5019 if you comment/uncomment the indicated lines of code.