Replacing Power Supply--fan cable problem

I haven't been able to find an intermediate connector cable.
Captain Nemo wrote on :

All - I'm replacing the power supply in my G4 minitower. The old 12v fan cable has a 1x2 red/black connector. The new 12v fan supply has a 2x2 yellow/black ATX 4pin connector (it's square vice 4-in-a-row).

I haven't been able to find an intermediate connector cable. Can some one help?

Thanks in advance... ...Capt. N.