What I personally do is play it on the ds2, transfer the save to an ez flash 4, then use a pokepatched platinum rom for pal park. btw, pokepatch allows d/p/plt to pal park with a GBA flash cart. YOU STILL NEED A GBA CART. It cannot be done without a combo of slot2 and slot1. There is currently no patch for hgss. ONLY d/p/plt. http://filetrip.net/nds-downloads/rom-hacks/download-pokepatch-42-f27240.html
Pokepatch is for the DS ROM ONLY. the only problem w/ using ONLY flashcarts is you cannot poketransfer from a flashcart to a flashcart. to use official poketransfer, you HAVE TO HAVE an ACTUAL d/p/plt cart. i concur with Team Fail. it IS possible. just not between b2w2 and a flashcart dpphgss. like he/she said, use poketransfer. if people gripe, bicker, and b***h lookin' for a patch for hgss, DON'T COME CRYIN' TO ME. take it up w/ the maker of pokepatch. I DIDN'T MAKE THE PROGRAM.