Yes, you can execute TS steps via CVI using the TestStand API. I am not sure how you are wanting to execute the steps though, i.e. are you wanting to execute the steps interactively or execute them using a process model? Either way you would essentially be creating a very simple version of an operator interface to execute the steps.
You would first have to get a reference to the TS Engine, then a reference to the test sequence file, (then a reference to the process model file, if you want to use a process model),then a reference to the test sequence within the sequence file above that contains the steps you want to run. Once you have this information you can call the Engine.NewExecution method to launch the execution. (If you are executing the steps interactively
you will need to use the TS API to create the InteractiveArgsParam parameter of the NewExecution method before calling the NewExecution method)
The above description provides a basic summary of how you could do this. For more details, take a look at the simple CVI operator interface that installs with TestStand in the \TestStand\Examples\Operator Interfaces directory.
Hope this helps. If you have a more specific question relating to this topic feel free to ask that as well.
Richard McDonell
Applications Engineer
National Instruments Corp.
www.ni.com/ask