A 240 as a Caribbean IMG does not really open any doors for you. What it does is (assuming you meet or exceed that score on Step 2) ensure that you will match, somewhere, in something. You're basically eligible for the same programs that any carib IMG can get, which involves all of the primary care specialties, surgery, radiology, anesthesia, PM&R, and a few other things.
It is definitely a good score, but basically it just gives you some sense of security that you wouldn't have had if you scored <220 on the exam. If you're looking to do something really competitive, you'll need to kill your CK, obviously pass CS first attempt... and then probably do a year(s) of research in order to get into your desired field... or if you happen to know someone high up, then having a 240 makes it easier for them to use a residency spot on you if it's a competitive field or a competitive program.