I have a macro in asterisk 1.6 for setting the incoming caller id. This is what is looks like:
[macro-SetIncomingCallerID]
exten = _!,1,NoOp(Call received in SetIncomingCallerID macro)
exten = _...
http://www.experts-exchange.com/Networking/Telecommunications/IP_Telephony/VoIP/Q_24432994...