I believe that if you purchase CI resale you'll get a RCI weeks account. So to deposit a week in RCI, you'll have to reserve a week at one of the CI resorts, then deposit that week in RCI. The number of points you'll need will vary from ~60 pts for a 1bd in low season to 250 pts for a 2 bd in peak season.
We own at CI and have other TS too. We most use our CI for point reservations at the many CI resorts. When we do trade we generally use II (not RCI) but that may not be available for you.
Hope this helps.