Make an ACD Path, cue for 1 second then Interflow it to VM Hunt Group, add the ACD Path DN as an alternate number to the mailbox, point all the DID's you want to the ACD Path.
Using an ACD Path makes the call control application "forget" the original destination/digits when it is interflowed, it only "remembers" the ACD Path DN and that is what is presented to Nupoint.