Result = UncompressPackFile(#Pack, Filename$ [, PackedFilename$])Description
Uncompress into the specified filename from the current pack entry being examined with ExaminePack() and NextPackEntry(). If the filename already exists, it will erased and replaced with the new uncompressed data.
#Pack The pack to use. Filename$ The filename to uncompress the current pack entry. PackedFilename$ (optional) The packed filename entry to uncompress. If this parameter is not specified, the current entry being examined with ExaminePack() and NextPackEntry() is uncompressed.
Return the uncompressed size if the pack entry has been successfully uncompressed into the filename, -1 otherwise.
OpenPack(), ExaminePack(), NextPackEntry()