[Freeswitch-users] Alternative to loopback endpoint?

Hi, I'm building an ESL conference application which calls/adds members after the conference moderator has entered ("outbound conference calls"). For this I would like to use the existing dialplan rules to decide if the call is internal or has to go over a specific gateway. In other applications I'm using the "loopback" endpoint for this, but it seems that I can't use it here, because if I'm using loopback then it plays the sound of the dialing into the conference. Is there another way to use the dialplan rules from ESL or a way to "silently" use the loopback endpoint? Thanks, René