Yep - You can boot to the WINRE (using F8 - Repair My Computer - then select the Command Prompt window)
You can use the OFFBOOTDIR amd OFFWINDIR switches...

...or you could do the same by using the repair function of your DVD
.... or you could slave the drive to another Win7 system.

but no, you can't slave the drive to an XP system and run it offline that way.