Message waiting light on multiple phones

[phadobas]

The voicemail system is AD64.
The phone system is SV8500.

Is there any way that if a caller leaves a message in a mailbox, the message light of not only the phone the mailbox belongs to turns on, but also another one?

To make it more complicated, that other phone is across CCIS on the 2400ICS.

 

[phadobas]

I found the solution for this.
Create groups on the AD64 and put the phones in those groups.
Sorry for wasting your times here.