Hi Neil,
You are really on the right track with this;
Here is the CUE method;
"Announcement Only" Mailbox
You can use either the Cisco Unity Express AA or a voice mailbox in order to play an announcement to callers that changes frequently (perhaps daily or hourly). Cisco Unity Express does not have a direct feature or mailbox type called an "announcement-only" mailbox, but you can use various other Cisco Unity Express features in combination to achieve this operation.
AA Application
The Cisco Unity Express AA is the most flexible way of implementing an "announcement-only" mailbox implementation. Write an AA script that plays an announcement (prompt) to callers. The simple example file (Announcement-mbox.aef) Associate this script with a pilot number (in the same way you would build a Cisco Unity Express AA application). Callers to the pilot number will hear the announcement and the call will be automatically disconnected by the Terminate step.
Building the "announcement mailbox" application using the Cisco Unity Express AA features has the following characteristics and tradeoffs:
The person making changes to the prompt recordings and assignments requires AVT access (to gain this access, define a group with the privilege to access the AVT and then add the users that must have this access as members of the group). This provides automatic PIN authentication so that only designated administrators can make changes to the announcements.
From this good CUE doc;
http://www.cisco.com/en/US/products/sw/voicesw/ps5520/products_implementation_design_guide_chapter09186a0080406670.html#wp1015952
Hope this helps!
Rob
