I believe what you are looking for is the LabVIEW SoftMotion Module:
https://www.ni.com/en-us/shop/software/products/labview-softmotion-module.html
Here is a good resource on stepper motor theory:
http://www.haydonkerk.com/Resources/StepperMotorTheory/tabid/192/Default.aspx
My other recommendation would be to start from a LabVIEW counter example. These can be found in LabVIEW>help>find examples>Hardware Input and Output>DAQmx>counter input, counter output.
RF R&D
National Instruments