Vista didn't catch my existing xp. No dual boot option.

Abit IC7-G w/SIS and Intel on-board SATA raid. I ended up reloading everything. I installed xp on the SIS raid. System wants to boot the intel raid set first(bios only lists onboard SATA). It doesn't show SIS or Intel. I had to unplug the intel drives to load on SIS set. Leaving the intel set unplugged, systems behaves as expected. After getting xp installed/updated, I shut it down and reconnected Intel set(ich5r btw). I booted with the vista cd and pointed it to the sis and intel f6 drivers and those sets appeared as useable drives in vista setup. I installed it on the intel set assuming that it would at least see that the xp install was there and bootable. Can I use bcd or EasyBCD to manually add the SIS set to Vista bootloader. If not, I can backup the whole drive sets to my 5th drive and swap the drives to the other controllers. Then I can just restore to the correct sets. The intel controller is scanned 1st in post, then the sis. I'm just curious if I can manually add a drive as you would with a boot.ini.
Thanks,
Steve