How to create a conference when dialing out

In the extensions.conf how can I dial out and put both caller and recipient in a conference??

exten => 123,1,Answer()
exten => 123,n,ConfBridge(something)
exten => 123,n,Dial(SIP/${EXTEN})

Use Originate for the outgoing call and then place yourself in the conference. The Originate should invoke the conference application directly, or lead to dialplan that does.

Also you can use G option on the dial command

Drops both channels into the specified context, extension and priority when the call is answered.

G(context^exten^pri): If the call is answered, transfer both parties to the specified context and extension. The calling party is transferred to priority x, and the called party to priority x+1. This allows the dialplan to distinguish between the calling and called legs of the call (new in v1.2). You cannot use any options that would affect the post-answer state if this option is used.