Hi, I was configuring the similar setup recently:
1) I created a new VM box (199 in my case), set mailbox type = "Message Only"
2) From the phone I initialized the mailbox (set the password, recorded name and welcome message and so on)
3) Then from the administrator's mailbox set the parameters for 199 to 11 (this probably removed the ugly message "Please hold while...." but I'm not sure now)
4) Uploaded a new welcome message to the 199 mailbox (this will replace the message recorded in 3) for a nice one)
5) Created a new Business Schedule (make sure your version is MCD 8.0 or later)
6) Created a hunt group *199 with type of NameTag with no members
7) In Call Rerouting for the extensions I assigned the business schedule defined in 5) and set rerouting always (Night 2 in my case) to *199
During Night 2 when somebody calls the extensions the call is rerouted to the VM box, a message is played and allows him to record a message. I hope it helps.