This conversion basically represents a making of a template (.mzt) out of a compressed file (.mz) in Mozart music notation software. It is unlikely that this can be done using any other software, so using the original tool seems to be the only option.
Convert Mozart compressed file to MOZART template file.
We have found one software suitable in our database for this conversion.
Microsoft Windows software - convert mz to mzt on Windows
A music notation software for Windows
Convert from mz file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.