"Global" Do Not Disturb?

Hi, I’m running Asterisk 1.6.1.6/FreePBX 2.5.2.2

I installed the do not disturb module, but this only appears to work on individual extensions when the feature code is dialed.

I have the following phones:

Cisco 7970 SCCP
Cisco 7960 SCCP
Cordless phone system tied to an FXS port

I have a ring group setup to ring all of these phones when an inbound call comes in on an FXO port.

Ideally, I would like the ability to pick up any extension and active DND to set it for ALL of these devices, is that possible?