Deleting trains

In a map, I have a CPC portal emitting trains to travel a specific route. After they have done this several times, I inserted a Delete train rule to prevent having too many consists on that route. The problem is that even though it is the last command, it gets executed as soon as the train is emitted by the portal. Without the Delete command, everything works fine except that eventually there are too many consists on that specific route.
Is this the wrong way to use this command?
Should it not be used in a CPC portal command string? I have the basic commands in a schedule library and use append command from the schedule library to add to the driver's list of commands.
Is there a way to emit a specific number of consists and no more?

Not 100% sure, but I think the 'append' option, for Copy Commands from Schedule Library, places them after any other commands in the schedule. I have always used 'insert' and have at Drive to Trackmarker type command before the final Delete Train request. This works fine using QuickPortalManager, so I would assume it should work using CPC (I have not used that rule to date).

I don't use the CPC but do have a setup like what you are trying to do. It should also work with CPC. Set up the schedule library for the route and in the driver setup using the insert from library command select the scheduled route to be used. Repeat the insert command for the number of times you want to run the route and then use the delete command. This runs the schedule until the last insert is used and then it deletes.

Following more testing, I found that adding a track mark did the trick. By placing the Delete command after the Drive to track mark, the consist doesn't disappear prematurely.