MSCZ, (it's not a typo) format is used as backup of MSCZ files, so this conversion is same as mscz to bww conversion, provided you can recover the .mscz, files using MuseScore first. Once this is done, you can simply use the Save as.. function to convert the notation to Bagpipe Music Writer's .bww files.
Updated: August 22, 2023