Do you mean the plug that plugs into the logic board's connector?
That's just a standard Molex Mini-Fit Jr. connector, like used on modern ATX power supplies.
You can either get a 10 pin (2 row x 5 pin) plug with the pins, and a crimp tool, to make your own.
Or you can grab a scrap ATX power supply, and cut down the main plug to 10 pins (do make sure the plug lines up shape-wise with the connector on the motherboard, the individual plastic pins are shaped differently to prevent wrong insertions), after which you can just solder the right ATX power supply connections to the wires still attached to the cut-down plug.