Hi
I always reply to mine when find a solution , if it can be useful for someone.
Some code must be added to file /etc/asterisk/extensions_override_issabel.conf
[from-trunk-sip-"NAME OF TRUNK"]
include => from-trunk-sip-"NAME OF TRUNK"-custom
exten => .,1,Set(GROUP()=OUT_X)
exten => .,2,Set(CALLERID(num)=0${CALLERID(num)}) <--------- I need to add a 0 but anything can be added
exten => _.,n,Goto(from-trunk,${EXTEN},1)
Bye