glad to see you got it working, and yes i made that script so it copies magic.lgp into the temp folder and then it extracts it then delete's the copy (this is because if you don't delete the copy it would be in the new LGP you build) leaving just the files, you can edit the files then to repack just make a rebuild.bat like i stated before (and put the rebuild.bat in the same folder we put the extract.bat)
its very simple, the hard part is doing it for the first time and finding the right DOS commands for what you want to do.
