Your question is not really that clear, but I am going to take a guess as to what you mean.
You have an Asus p5q pro and it only has one firewire (IE1394) slot on the motherboard (the 10 pin - minus 1 pin - connector on the mobo) and for some reason have more than one firewire port on the front of your case. Most motherboards have firewire ports on the back, and pins for the front port headers.
If you really need another 1394 port, get a hub, plug it in, and you should have multiple 1394 ports.
DO NOT PLUG IT INTO USB.