Hi,
In fact that's not what I was looking for, I already saw that explanation and made the "partial" (in fact, localise the workbench itself, except extra parts from classicwb pack) localisation.
I was especially searching for classicWB itself french catalogue. On french forums, some users gave me this link :
http://tarzin.free.fr/catalogues/ClassicWB_v24.lha
But I didn't try if for now since I'm making a deeper test of BetterWb.