Sry, I can't edit the previous post...
So, tested and corrected some of my mistakes :
1. It's %~dp0, and not ~%...
The "getmac% gives me a lot of info... too much in fact :
Adresse physique Nom du transport
=================== ==========================================================
AA-BB-CC-DD-EE-FF N/A
is it possible to have "only" the mac address ?