Patching a game is quite easy. Use PPF-O-Matic. You can find it here :
http://www.megagames.com/dc/dc_ppf.shtml
You'll often need to have the original file in order to apply your patch. If you don't have it anymore, try to make an iso using the same burning program than the one your patch was made for (for example, DiscJuggler if the patch needs a CDI file, or CDRWin if it needs an ISO or BIN file).
Run PPF-O-Matic, select your patch and your iso and then just apply the patch.
PAL Patcher should convert some 50 Hz games to 60 Hz (the latest version should convert also 60 Hz to 50 Hz). But it's first purpose is to have some games works on PAL DCs.
Except PAL Patcher, I don't know many programs that automatically patch files. You might try PAL2NTSC. It might work.
http://www.megagames.com/dc/dc_utils_patch.shtml
Let me know.