ROM Hack Copying a SAV file from Pokemon SoulSilver/Pokemon Black to flashcart?

[LittleBigMods]

I believe I've done this before using my DSi but I can't remember how. I know I was able to copy my SAV file from my SoulSilver Version onto my flashcart but I don't remember what app I used so I can put it back on my original game. Also I would like to know if I can do the same with my Pokemon Black Version, using a DSi, rather than a DS Lite.

Thanks in advance for any help