You might be able to use a cloning program to clone the xp install into the BC partition from within Parallels' XP ...
Haven't tried it, but it might be worth a shot.
A couple of things to keep in mind here with this approach.
It would require a reauthorization of XP since the hardware changed.
Would be best to uninstall the parralles drivers.
Provided you can even SEE the bootcamp partition in parallels it may be possible.
You could get prompted for the disk to install new drivers that aren't present in the Windows\System32 directory.
Everytime I see "I've lost this cd, that cd" I get skeptical. Sure I've lost things and disks before but I've sucked it up. OS Disks however are like your underware (other jokes aside) you really don't want to tell someone "I lost my underwear so Im not wearing any"
If you have the CD Key you can always download/torrent or borrow a disk and use your cd key and reinstall. The torrent part is risky but you at least DID or DO own a legit cd key (assuming).
The cloning software might work (paragon, ghost, etc) but if it's a trial version it might not do everything. In the end it might be cheaper to buy a new disk or request a replacement. The cloning since your cloning from a virtual disk to a physical drive might pose issues though. Remember, bootcamp doesn't have an MBR and some cloning programs modify the MBR to allow the drive be bootable.