Lookup list filter only future events

Question

I have a task list that assigns tasks to specific future events. The custom task has a lookup column that is based on an events calendar. Is there any way I can cleanup this lookup list to only show events that will be occuring >=[Today]? I would write a calculated column in the events calendar, but you cannot use [Today] or [Me] in a calculated column.

Perhaps I should just set the events to delete after they've occurred?

Answer 1

I solved the issue by setting the retention policy on the event's calendar to delete item the day after the event. This leaves the custom tasks assigned to the event 'orphaned,' as it removes the data from the event lookup column. I suppose I'll setup a retention policy for these items as well.