So after some testing a poking around with VMPro this is actually possible by using a Generic command to Set the do_not_disturb var on a user to 0, then using a custom variable setup that increments by one to apply to an extension range until it hits a defined limit.
I found that adding the extension to the DND exceptions does not work because I was using a group, you just get a busy signal if you try to Dial Paging that group.
Not an ideal solution I know, but it's what we've got to work with.