exten => s,1,SetGROUP(${ARG2})    
exten => s,2,GotoIf($[${GROUP_COUNT()} > ${ARG1}]?104) ;Exceeded?
exten => s,3,NoOp("MADE GROUP CHECK found ${GROUP_COUNT()}")
exten => s,4,Set(PRI=TRUE)
exten => s,5,NoOp("");SetCDRUserField(PRI)
exten => s,104,NoOp("MADE PRI CHECK EXCEEDED found ${GROUP_COUNT()}")
exten => s,105,Set(PRI=FALSE)
exten => s,106,SetGROUP(SIP))