You can choose an announcement as the destination of a custom application. If you didn’t see announcements it must have been, none existed when you tried to create the custom application. Here is a screenshot and its been present for a long time.
You can also create a Class of Service choosing your outbound route and set pattern based dial restriction rules that point to your announcements already. You just have to make sure to create the Outbound route and your Dialrestrictinos before you create the Class of Service . Then set the Class of Service on the extensions.
Dialing Restriction Rules
