It is working =)
I am using the ON_EVENT "CreateModel"
which returns the "modelid" which i can now use to access the current active model / shown model.
ON_EVENT "CreateModel"{ EXECUTE file: "db:\\scripts_predefined_objects.asc" CREATE_PREDEFINED_OBJECTS nModelID: ( modelid )}
The solution is described in:
https://www.adoxx.org/live/en_GB/faq/-/message_boards/view_message/354495#_19_message_353322