Following situation: I have a calendar with events, where attendees can register. When the event starts a topic for the event is created in a discussion board. When it is created every attendee should receive an email with a link to the topic. For this every topic in the discussion board has a column "discussionID" which is the ID of the event. But when i add a lookup to the "URL Path" it is just empty. Any idea how I can link directly to the topic? Attendees should not be able to access the overview page where all topics are listed. They just should be able to access the topic via the link, and of course post there.
Any help is appreciated!