[Serusers] SER handling group calls ?

Hello, I've got version 0.8.12 running on a linux box and are trying to setup a group call, ie B & C register with group1. Then A makes a call to group1. SER is forking the INVITE's to both B & C as expected but they both reply with a 200 OK and SER sends both 200 OK's back to A. I've read the mailing lists and docs but couldn't find anything on how to do group calls, only things like hunt lists or forwarding on busy. There seems thin docs on how SER handles responses in the scripting langauge, ie I have 2 or more 200 OK responses and need to deal with them appropriately. Am I right in thinking responses do not go to the routing logic ? Does SER handle group calls easily or will I have to use something like the exec_dset or is this anything in the tm module for this ? Any help appreciated, Nick Wilson