After reading your post again, i think i may have missed an important point of your question.
You currently have booked your owned week for use - which is your exclusive right 6-12 months out. You don't trade in Interval with that week - you can only book in Interval with points. So if you want to book in Interval you will have to cancel your reservation to get your points back. Once you use any of the points from that week you have lost your exclusive right to your week.
Once you have your points back, you can book in Interval thru your Interval portal and it will use the points from CUP. But I prefer to move them to EEE before booking and it will pull from EEE before it pulls from CUP. I do that because i want the life of the points extended - which comes into play if you ever cancel your Interval reservation.
As I mentioned above I do use points for a combination of Interval and Hyatt reservations - but it requires planning. EEE is great with the points extention, but they cannot ever be moved back for Hyatt reservations.
Using a points system for Interval works differently that turning in a week for a week. For example, you cannot upgrade your unit size since the points requirements change. Changing from a 1br to a 2br will require extra points.