If you look at your m10000 board you will find you have another com port on board, you just need to get the correct lead for it. I was going to buy the M12000 board thats just come out, but I dont think that has the extra com port needed..
thats what you need, you can get them almost anywhere.. :-) All I did was remove the backplate and hot glue the interface to my pc case i've made.
once the carpet bit is put back you will only see the first 2 inch's of the case, where I drilled some holes for the vent, and put a usb socket.. coz you never know when it might come in handy :-)
cheers
CdR