What do you mean by "the list"? Do you have an ongoing search in place for Manhattan Club?
I've traded into MC three times. Manhattan Club is not all that hard to exchange for through RCI, but to do it you need to have a very strong trader, and an understanding of when the resort makes its deposits available. If you have a strong trader, put in your search 18 months in advance, and are open to a broad range of dates, then you should be successful.
If you request one specific week (i.e. July 4th, 2008), I would guess that the chances of success through RCI are very limited.