I'm not quite sure I understand correctly what you're trying to do. The question is whether you have all your music files on your laptop including those on your iPhone. If so, then why not try importing them from your laptop to MusicBee? You can either import only selected folders to MB or delete unnecessary tracks from MB after importing all, as importing means simply letting MB know where the music files are located unless you're gonna auto-organize your music files with MB. But, importing songs from iPhone to your laptop is not supported by either MB or iTunes, and you will need to use a third-party app.