Setting for provisioning voicemail number

[kg4ysy]

I've looked everywhere and I can't find if there is a provision setting for setting the voicemail number (*86 in my case). On a related note, I noticed that the phone is not pulling it in from the SIP switch. After a SUBSCRIBE a NOTIFY goes out that includes the line below. If the phone could pull that in, that would be great, but I'm fine with setting this in a provision file.

Message-Account: sip:*86@192.168.XXX.XXX:5060