Extension delay with ring groups

I have a FreePBX running with ring groups configured, and one of the ring groups includes a external (mobile) number. As it is configured now, the mobile number is dialed along with the other extensions. How can you delay an external number or internal extension, so its starts ringing say, 10 seconds after all the other extensions start to ring?


create two groups. one that you all want to ring together, then create another group that calls that group and the cell phone and use the hunt option. that way it will try the ring group without the external number first and of no answer then call the mobile.