No, you cannot run it from a disk that way, but you could copy XP's disk into a VM, which runs from a virtual disk that is located on the old drive.
Simply put, you basically clone the XP system as a file somewhere, erase the drive, set it up for use with Virtualbox, and then copy the clone back into the VM.
Again, that's the short version. It's not a trivial procedure, but it can be done.