You can put the ghost on to a different partition but getting it to work is the tricky part. I think you might be able to do like you said then boot from the xp cd-rom and do a boot repair but I have had inconsistent success with that. If you have room on the new drive then try this, do like you said then do a new install on the C: drive. Modify the boot.ini afterwards to point to the D: drive and you should be set.
This one tells you about the boot.ini
MS KB 289022 The OS should work fine but expect a few things to be screwy because of the drive letter change. Unless you really need something from the current XP install you would be better off just doing it from scratch.
By the way, I have never tried what I just recommended
