Yes, you can call MS with the range of dates and area where you are interested in staying. If there is a match right then you can make the reservation and the points will be taken from your account. If nothing is available at that time, you can also request an ongoing search where you would be notified when something becomes available or you can go ahead and bank your points into the World Passport Collection and use the search to get you a match when it becomes available.
I would begin as far ahead as possible to improve the chances for success since many of the more popular locations will be sought by other RCI members as well - and they will have access to the same options (they will have already banked their weeks/points) as well as online access to the RCI system. If possible, I'd start looking 2 years in advance, but at least a year would give you a better opportunity to get the dates and resort you want.
Good luck!