Sync ratings FROM portable device TO main MB library ?

[Bifidusse]

Hello there,

All my music is now into a MB library. I don't have words to describe how this is GREAT 

I'd like to listen to those songs when I'm at the office.

To achieve this, I thought to :

- copy all music files to a portable HDD ;
- listen and RATE songs when I'm in the office (playing songs from the HDD) ;
- sync ratings (or copy files newly rated) FROM the HDD to the main library (on a NAS) at home.

But the sync feature seems to work FROM the library TO the mobile device only.

Is there a way to achieve this with MB ? Or should I use a sync utility within Windows ?

Thank you 

[Bifidusse]

I found a workaround. I use FreeFileSync. Not fully automatic, but almost.
This software compares 2 directories (the one from my usb disk and the main library on my NAS) and synchronize both ways. New/modified files on NAS go to the usb device, the same from the usb to the main library (mainly rated songs when I was listening from the usb disk).

I made a shortcut for the task, I just have to double click on it and directories are synced. It's very fast (~40000 songs).

That said, it can be dangerous : if files are damaged on the usb, FreeFileSync could overwrite the "good" files of the library. So, make backups