The left side of your query implies there is an equal with the right side, hence the message about =, !=,<,<=,>,> =. If it were a select query with this problem, it is possible to use the IN clause to deal with multiple values on the subquery side, but I don't know if that's possible with an append query. I don't know where I'd put the IN operator between the two queries, and I doubt it would be WHERE CourseID IN, since that locates it in the subquery side. Even if it was correct, I'm fairly certain you will not get it to work in conjunction with the LIKE operator. Another possibility for dealing with record sets that comes to mind is HAVING as in
(select ElementID from CourseElementsDefault Group By CourseID Having CourseID LIKE '" & Me.CourseID & "'))". I've been cutting and pasting here, without really checking the syntax with respect to quotes and such, so take care with that.
You could play with these ideas, but I'd do it on test tables.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.