[macro-res]
exten => s,1,Set(GROUP()=res)
exten => s,2,GotoIf($[${GROUP_COUNT()} > 1]?104) ;Exceeded?
exten => s,3,NOOP("MADE GROUP CHECK")
exten => s,104,SetVar(DIALSTATUS=CHANUNAVAIL)
exten => s,105,hangup()