[Freeswitch-users] transfer aleg via ${dial-string}

I want emulate REFER message from bleg via ${dial-string}. Please help me find how to do it. I try 1) originate sofia/internal/sip:1000@8.8.8.8 &bridge({execute_on_ring='transfer 1001 XML default'}loopback/9180/default) 2) originate sofia/internal/sip:1000@8.8.8.8 &bridge({execute_on_ring='transfer 1001 XML default'}sofia/internal/ sip:1002@8.8.8.8) In both cases all leg hangup. Also two question: 1) can be lua or other scripting language used to emulate endpoint (implement endpoint interface)? 2) how can be realized "execute_on_channel_create_failure" logic similarity "execute_on_ring". Sergey