I do know that if you a laptop with a output port you can extend the monitor. Ex: windows interface displayed on the laptop screen and just a wallpaper displayed on the external or vice versa. However with a desktop i am not to sure if this can be done.
you will need one monitor with a d-sub (vga) and another with a display port cable or adapter. though it would be advisable to contact dell and ask them if you need to enable multi monitors for the hd 2000 in the bios.