serial port needed to fix car

[xv6700user]

So I have a program that will allow me to mod my car's computer, I use it for from my laptop with a usb to serial adapter and then have a special serial to DBII to plug into the car. I have the PPC version of the program and want to have it for emergancies (crazy old range rover air suspension) but I don't know what options i have to plug a serial cable to my xv6700. I don't need anything fancy, like bluetooth to serial. is their a usb reverser that would make my mini-usb on the phone convert to a full size usb to use the usb to serial converter?

software is:
http://rangerovers.net/forum/viewtopic.php?f=8&t=22842

Thanks!