Possible to upgrade a graphics card in a Latitude e6420?

I recently purchased a Latitude e6420, not realizing it was running HD3000 graphics, is there any way to upgrade this to HD4400? Or even to a non Dell card like a GTX970? I realize I should have done my homework and discovered before making a purchase that I was buying a rig with such an inferior card, but I was doubtful that any laptop running an i7 processor would be running such a bad graphics card.