Hi David,
I'm afraid FL4 (FL3 too, for that matter) is bound to the EHM time-table. So any of the legs that has a flight number in the Flights database can be flown for EHM using the logger.
If you want to make it a PP flight even, then also an appropriate airplane must be available at the departure airport. You may have to fly one in especially for the purpose

Of cause you can fly the legs, online on IVAO, using an EHM callsign, but that just cannot be logged (assuming none of the legs are in the timetable), and it won't get added on your EHM flight hours.
Eric-Jan