You can also use rsync if you add something new to your laptop and don't want to copy all of it. This is what I use on my Mac:
rsync -rlv --delete --size-only /Users/myname/Music/Rips "/Volumes/music_store/USB/USB DISK/"
I use --size-only, because normal rsync doesn't work very well over this particular Samba mount - it used to sync lots of unchanged files.
Before you do any of these, you need to change Samba permissions, by default the USB mount is read only. To change it, you need to modify /etc/udevil/udevil.conf. Find default_options_vfat and default_options_exfat and change ro to rw.