asterisk users - Aug 2010 - Polling DND status of a Linksys SPA9xx/5xx phone?

Hi,
Is there a way to poll the DND status of a Linksys SPA9xx/5xx phone?
The reason I ask is that I'm trying to implement DND + BLF on asterisk.
However, the DND softkey on the Linksys phone does not send any
feature codes to asterisk.
On the flip side, if you disable the Vertical Activation Codes on the
phone, then dialing the feature code doesn't display 'Do Not
Disturb'
on the phone.
What I need is an indication on the phone that it is on DND, AND an
indication through BLF to other users that a particular phone is on
DND.

Any ideas?

Thanks.

-- James