Are you talking about extending the USB ports on the motherboard or extending the USB hub headers on the motherboard (the ones with pins) like this one?
I'm not really sure. All I know is that the regular USB extension cables that you connect to the USB ports on the outside of a computer case will not work for at least one of my devices. This particular device needs to be connected directly to the USB port itself, but the cable is not quite long enough. It's possible that I could get a longer cable for my device. But, I was just thinking that there could be a way to extend the cable that goes from the motherboard to the USB port. However, it might seem strange to have an internal USB wire extending several feet outside of the computer case.