I'm not sure about getting it through RCI but, it seems to be getting more difficult to even get it as a HGVC owner. Hilton keeps building and selling more units in Las Vegas and Orlando, but sells heavy on the idea that you can own those weeks and exchange into Hawaii, which seems to be what everyone wants to do when they buy in. If you keep building in Vegas and Orlando and use Hawaiian exchanges as a selling card, eventually you'll have to many non-Hawaiian units trying to trade into Hawaii.
Last year, we used our Vegas week to exchange into Hawaii for the first time. We had always heard how easy it was to exchange into HHV with our Hilton ownership. It wasn't difficult but, the best we could do was a 1 bedroom ocean view. I was hoping to combine two years worth of points and upgrade to a 2 bedroom ocean front unit. It never became available for the week we were going. While I did see 2 bedroom island views available they didn't remain available to Hilton members for very long.
So, based on my personal experience just trying to get an internal exchange within the HGVC system into Hawaii, I wouldn't say your chances are great. I woudln't say it's impossible becasue I'm sure HGVC has a contract with RCI that guarentee's at least a minimum of units be avaible for exchange but, my bet is those weeks are popular and tough to get.