Hi Daniel,
I desactived my feature and I tried with this code (without result) :
File: /etc/asterisk/extensions_custom.conf
[from-internal-custom]
exten => *66/_XX,1,NoOp()
same => n,Answer()
same => n,Set(result=${CURL(http://admin:password@192.168.1.151/preset.htm?RLY7=1)})
same => n,Hangup()
and I got this result. (sorry if i copied too much)