Yes, it's possible to apply a call forward to a hunt group or ring group, using Call Forward Follow Me - Third Party. I do this now on the system I currently manage for department main numbers. We have speed calls programmed to enable CFFM-3rd party for the hunt group/ring group, and other speed calls set up to cancel. So when the department leaves for the day, they just dial the appropriate speed call (programmed as a CDE Speedcall key on the reception phone, normally), then turn it off when they open the next morning.
