Adding custom statements is possible but it requires some experience about python and VC APIs. For example this add-on is a custom statement:
https://forum.visualcomponents.com/t/waitstatement-for-robot-programming/
For custom statement you typically need a python add-on which creates new button on the program statement gallery. With the add-on you define a set of properties for the statement to store data. Then the statement is associated with python process handler which defines execution logic for the statement. For your case it would be just an empty placeholder if statement doesn’t actually do anything during sim. Finally you would need to modify post-processor to identify and handle your custom statement.
More info about custom statement can be found on app’s help file under topic “vcPythonProcessHandler”.
-k