Nvidia quadro 135M question PLEASE HELP

Hi guys,

quick question

I have a dell D630 and i want to run three monitors independently, i know i can run 2 because i have the PR01X docking station which has both a VGA and DVI port wich the 135M picks up.

What i was wondering is can i get a usb to dvi adapter to run a third monitor and with the 135M pick up ther third monitor to be independent of the other two.

I have been slaving over this for days trying to find a cheap solution withought going with the MATROX. please help!