Leslie - if you're referring to using like 6,000 points for a suite upgrade for up to 4 nights, you should be able to get back the points and use these certs for (valid up to 7 nights) instead. However, many Hyatt Customer Reps are rather poorly trained these days, so you might get one that says you can't. In that case, just hang up and call back (I find the best agents to be working late on weekday evenings Eastern Time - which is counter intuitive).

I've never tried this personally, but I would think the procedure is the same as converting existing award reservations on points to Faster Free Night (or whatever they choose to call "new" versions - when they are running) redemption. Many phone reps will tell you it can't be done.

Another alternative to get an agent that is knowledgable would be to Private Message the Gold Passport Concierge over on Flyertalk - at least there are people who keep them "trained" aside from the official training.