Regardless of whether it has 2x DVI or not, you cannot hook up 2x DVI + 1x HDMI to any of the older Nvidia cards. These cards are limited to 2 simultaneous video outputs. The only way you would be able to hook up 3 monitors to that computer is if it provides a video out for the CPU's integrated video, in addition to the outputs from the video card. Somehow, I have a hard time believing that Dell systems would allow end-users that degree of flexibility.
Connecting 3 monitors to one video card is only possible with ATI/AMD cards, using Eyefinity, or with the new Nvidia GTX 680.