Sorry, but I do not know what a Freebox folder is.
But, if you run Windows OS, then use Winaero Tweaker! I use it for a lot of customizations, and it has a settings backup and restore for re-installs!
Mods... I am really sorry if this is being naughty, but the guy needs help, and I had to search the Internet for a long time to find a solution to customizing the explorer nav pane! Give me a link for the rules if I 'goofed up' again!