I am Jean-Michel Leban a French citizen. My grandfather came from Slovenia, a small village-Volce- located near Tolmin.My grandfather's brothers were living in Tomin.
In our familly, it is said that the origin of this French name Leban in Slovenia is explained by one French soldier from the Napoleon's army. When the Napoleon's army was defeated, this soldier decided to stay in this part of Europe.
Hope that these information can help.