That's possible and several manufacturers make a "power" cable only.

However check it out closely just in case the other wires are tucked up/trimmed out of sight.

The other option is to check the price difference between a "normal" power/data cable (loose wires) as opposed to a specific PC/data cable complete.

If you can handle soldering 9 pin DB connectors then the price difference might be worth it?

Cheers, Kerry.