If you simply want an external call to come into your system and based on the DNIS get routed to a greeting, there is no scripting involved in terms of CC6.
You would use application builder to build the greeting or menu, go into call pilot SDN, create a new SDN and associate it with that application you built, build a phantom for that SDN so the phone switch recognizes it, and lastly build an IDC entry to point the DNIS number to the SDN.
If the call is already queued in the marketing skillset and you want some sort of hold message, you're going to need scripting within that CDN to take the call out of CC6 and over to call pilot to give the hold message. This part I can't really help you with as I'm trying to learn this as well.
Matt
CS1000E VoIP
CCM 6
CallParrot
CallPilot