Perhaps this is a way to grind it out:
My idea: as the playlist does not contain the path, the files have to moved (temporarily) to a single folder and then the playlist can be applied. And with that information, the files could be moved back to the original location and a local playlist can be created. These would be the steps:
- Load all files into MP3tag.
- Select all the files
- Create a user-defined field to store the original path:
Format value for (e.g.) OLD_PATH
Format string: %_path% - Move all the files to a single folder.
Use Convert>Tag-Filename
Format string:E:\playlist_temp\%_filename% - Make
E:\playlist_temp\the working directory - Drag&drop the Spotify playlist into MP3tag.
Hopefully, MP3tag now loads all the files from the playlist - Select all the files
- Now move all files back to the original location:
Convert>Tag-Filename
Format string: %old_path% - Select all files (if necessary)
- Create a new playlist
- Load that playlist into iTunes and see whether it works.
Once the process is over, you can delete the field OLD_PATH
... it could be that not all the files were addressed by the Spotify playlist. These would remain in the folder E:\playlist_temp\. To restore your old file structure, you would have to load E:\playlist_temp\ again an move the files back to the original location as described above.