Hi, you should be able to buy a wire that will convert the standard pin plug into a molex plug (the ones used by the pata hard drives). You can find them on newegg: something like this:
Newegg.com - Link Depot POW-ADT-3P4 Power 4 pin adapter to 3 pin fan adapter - Adapters & Gender Changers

That may not be the exact kind you need, but look around, I'm sure there's at least one. Good luck.