Is it possible to give a caller an option during a voicemail greeting to press #1 and the system route them to a predefined number within Call Manager, say a route point?
yes, configure caller input.
create a dummy call handler and under transfer options set it to, yes, calls subscriber at this number and type in the number you want to reach
on the subscriber configure caller input X to attempt transfer to dummy call handler
make sure restrictions tables allow this and the that the CSS of VM ports can reach the number
if this helps, please rate