Can you be more specific about what you'd like to do (i.e. what the customer wants to have happen with such a hybrid install)?
The personal call routing rules in CUC are tied to the subscribe mailboxes for users as well as ASR conversaton related features (i.e. "Call Mom at Home") - it's not really something you can have live on a Connection system but tied to a subscriber's mailbox on Unity.
Perhaps if you have a specific scenario in mind for them it'd be clearer...
