You cannot trigger BatchPatch actions from cmd/powershell. However, if you want to automate the update process you can schedule BatchPatch actions to run at a desired datetime by using the Task Scheduler inside of BatchPatch:
How to Automate Monthly Windows Patching and Updates for Numerous Computers
If you want to be able to run BatchPatch scheduled tasks without having to be logged on with BatchPatch running, you can run BatchPatch as a service:
Running BatchPatch as a Service