Forward to voicemail with BLF light

[Hpijl]

Hello,

I have an costumer with an T46G. He is autoprovisiond with the Broadsoft platform.
On this phone, there are multiple forwards with speeddial on the phone with an Feature code of Broadsoft. (*72NUMBER) in this case.

There is also an voicemail button (*72999) that's sends al the calls to voicemail. They use it when they need to leave early, and the automatic nighttransfer is active later.

But when they use this key, they don't know if its on or off.
There is no light burning with these functions.
There is only an small arrow on the screen, but that is always there, because of No Answer forward.

Is there a way to enable the forward to the voicemail, with the BLF light on when enabled, and off when disabled.

I hope someone will know this.
THanks in advance