No, sadly you cannot. I am sure you can use the usual DOS Method's but I am unaware of the commands personally.
Here is the Video Flash Utility (VGA @BIOS) as well as HUD Gamer's tools >>>
GIGABYTE - Support&Download - Graphics Accelerator - Utility
However here is a Guide, a little old but I believe still relevant, for flashing from DOS and VGA Flashing in general >>>
techPowerUp! :: Guide to Video BIOS flashing
I think your BIOS comes with Nflash or ATIFLash right, those would be the DOS Tools you would need, a floppy, and a second card.
If you would like some specific Help that may be newer, please let me know your model of card and I will get you some ATI or Nvidia Based specific info