Ring Groups

I need to input cell phone numbers into a ring group that will ring at the same time. I need to make sure only one call goes to a cell phone at any given time (avoid call waiting). I need the callee to press 1 to accept the call.

It seems all these features are in FreePBX in one form or another, but I cannot seem to get them to work together.

From what I gather, firstnotonphone will give me the functionality of only one call to a given cell phone. confirm calls will give me the option to require the cell phone user to press 1 to accept the call. Ringall will do just that ring all the cell phones for an incoming call. However, ringall doesn’t ensure only one call goes to a cell phone and firstnotonphone doesn’t ring all cell phones at the same time.

How can I get this configuration ? Thank you in advance.