9-pin USB splitter for motherboard

I just built a computer.  My case has two sets of USB ports in the front, and my motherboard has two sets of pins to plug those into.  I bought a separate 3 1/2" multi-card reader, but it requires that same set of pins.

Basically, I need three 9-pin connections instead of the two built into my motherboard.

I have done some searching with no luck, online and off.  Is there such a thing as a splitter for that 9-pin set on the motherboard?  I assume since each plug already corresponds to two USB ports, the port doesn't care if there are multiple inputs, so a splitter would not be out of the question.

It's like the rectangular plug like in this picture (with one pin blocked off): http://www.mcmcomputers.co.uk/images/p1022_030p2.gif

Is there such a thing?  It doesn't seem like Micro Center, New Egg, or Fry's have a cable like that.

Won't work.  The port supports exactly 2 inputs and will care if you electrically split it.  4 of the pins go to one plug and 4 of the pins go to the other.  Read your motherboard manual more carefully.

You can sacrifice one of your sets of USB ports to install the card reader.  If you don't want to do that, you will need an adaptor that converts the socket on the card reader to a USB male plug.  They do sell these and they are somewhat expensive, but if you are savvy enough you could make your own.  Then, you have these options:
 
 - Run this cable to the outside of your case and plug it into a USB port when you need it, and unplug it when you don't.
 - Purchase a USB 2.0 PCI card, one with a 5th internal port (like Belkin), and plug it there.
 - If you are feeling especially ingenious, you can do this.  Purchase a USB hub, with four ports or something, and mount it on the inside of your case.  Plug the USB card reader into it.  You will then need another adapter to convert the main plug of the USB hub (the one that would go in the computer USB port) to the socket of the motherboard.  That is the only way to truly "split" a USB connection.  (They do make this second kind of adapter as well...)
 - Buy a new motherboard with like 20 USB headers or something