You can use XP with 10.7.x by installing XP when the Mac is operating from OS X 10.6.8. It can then be up graded to 10.7.x. Below I have reproduced the "Hatter " method instructions that I have used successfully. If your MBP cannot boot from and install 10.6.8 then it is a no go situation.
Upgrade 10.6.8 to 10.7 or 10.8
Use a maintenance utility like Yasu or Cocktail to prepare existing internal Mac OSX HDD.
Clone the internal Mac partition to an external HDD with SuperDuper or Carbon Copy Cloner.
Restart from the cloned external HDD and select it as the startup volume via System Preferences / Startup Disk.
Install 10.7 or 10.8 on the cloned external HDD replacing 10.6.8 or 10.7.x.
Install 10.7.x or 10.8.x updates on the external HDD
Restart the updated 10.7.x or 10.8.x external HDD and test and adjust the preferences if needed.
When satisfied, clone only the 10.7.x or 10.8.x external HDD back to the existing internal Mac HDD replacing 10.6.8 or 10.7.x but don't include the recovery partition.
The Boot Camp partition will not be altered as to drive id which appeared to cause problems for a few people.
The recovery partition will be on the ext HDD and can be used for trouble shooting. A more convenient way to have the recovery/reinstallation environment is to create a Lion install USB thumb drive.
