Yes, it can be done. It is however not something for the faint of heart.
Macs use EFI instead of BIOS. There is no support for EFI in XP, so you would need to do some considerable messing about with the EFI system partition in order to do what you want.
If you don't know what EFI or BIOS are, and how they work, you don't want to even go near this kind of idea. That said, if you fly something interesting I'm easily bribed
