Can I boot a pre-existing XP partition from an external drive?

I had WinXP installed on my 120Gb MBP via Bootcamp, but I've just recently changed the HD for a new 200Gb one because the original was starting to fail.

I had a backup of the OS X partition which I restored onto the new HD, but I don't have a backup of the XP partition. It wouldn't be a huge deal to reinstall XP from scratch, but I was wondering... if I used a SATA-to-USB cable to connect the old drive (which hasn't yet failed completely) to my MBP and then restarted using the option key, would I be able to boot from the XP partition on the external drive?

If so, I could then use something like Maxtor's free MaxBlast app to copy all the data from the external XP drive onto the new internal XP partition.

Any advice welcome... if it's not going to work, there's no point springing for the SATA-to-USB cable