First, messages left as part of the default system call handler will either be in the Operator voicemail box or in the UndeliverableMessages Voicemail box. Your system administrator can give you access to both via Web Inbox so that you can manage the messages already in there. Certainly someone should be monitoring those voicemail boxes on an ongoing basis anyway. To enable Web Inbox, the Operator and Undeliverable VM box accounts would have to have a Class of Service that allows for Web Inbox and each of the accounts needs to have a password configured. You can also configure the Opening Greeting to put VMs in the Operator VM Box rather than Undeliverable (or vice versa) so there are fewer places to check regularly.
CUCM does not have a "Transfer Reversion" feature. You'd need attendant software such as Cisco Attendant Console for this sort of feature.
CUCM does have the Directed Call Park feature, where you could park a call on the Nurse's phone - but that doesn't ring out loud. Park does have a reversion timer, though, and could return calls to your extension.
The only other CUCM-native option I can think of, and this would only work if you have a small number of extensions for this - would be to create a hunt for each target with the Final Forwarding Behavior to roll back to your extension. You'd put the Nurse's extension in a Line Group, add the Line Group to a Hunt List, and create a Hunt Pilot with a DN of something like their extension prefixed with a pair of * (so: **<ext>). Then you'd configure the final forwarding behavior of the hunt pilot to go back to you. This is a non-trivial amount of work so the number of these would have to be small. But it would work.
Let me know what you think about these options and if you need additional information or advice.
Maren
