This conversion seems to mainly represent using a template (.ftm) to produce a new music notation file (.mus) in Finale music notation software. It looks like pretty straightforward workflow, but it appears that you can only do this in Finale and no other program. Used to quickly make new files based on settings saved in the template.
Convert Finale template file to Finale music file format.
We have found one software suitable in our database for this conversion.
Microsoft Windows software - convert ftm to mus on Windows
One of the most popular music notation software on market
Convert from ftm 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.