[macro-portables3]
exten => s,2,Set(${ARG1}=${EXTEN})
exten => s,3,Dial(Zap/3/0033${ARG1},,g)
exten => s,5,HangUp()

[office4]
exten => 201,1,Dial(Sip/201)
exten => 200,1,Dial(Sip/200)
exten => 202,1,Dial(Sip/202)
exten => 203,1,Dial(Sip/203)
exten => 208,1,Dial(IAX2/208)
exten => _006XXXXXXXX,1,ChanIsAvail(Zap/3)
exten => _006XXXXXXXX,2,Cut(PORT=AVAILCHAN,,1)
exten => _006XXXXXXXX,3,Set(FOO=${IF($[${PORT} = Zap/3]?Macro(portables3,${EXTEN:2}):Dial(Zap/4/0ww${EXTEN}))})
exten => _006XXXXXXXX,4,Exec(${FOO})



Accepting AUTHENTICATED call from 192.168.0.76:
       > requested format = gsm,
       > requested prefs = (),
       > actual format = ulaw,
       > host prefs = (ulaw|alaw),
       > priority = mine
    -- Executing ChanIsAvail("IAX2/208-1", "Zap/3") in new stack
    -- Hungup 'Zap/3-1' <<<<<<<<<<<<----WHY????
    -- Executing Cut("IAX2/208-1", "PORT=AVAILCHAN||1") in new stack
Sep 19 17:12:26 WARNING[22105]: ast_expr2.y:843 op_div: non-numeric argument
Sep 19 17:12:26 WARNING[22105]: ast_expr2.y:843 op_div: non-numeric argument
    -- Executing Set("IAX2/208-1", "FOO=Macro(portables3|686167128)") in new stack
    -- Executing Exec("IAX2/208-1", "Macro(portables3|686167128)") in new stack
Sep 19 17:12:26 WARNING[22105]: app_macro.c:151 macro_exec: Context 'macro-portables3' for macro 'portables3' lacks 's' extension, priority 1
  == Auto fallthrough, channel 'IAX2/208-1' status is 'UNKNOWN'
    -- Hungup 'IAX2/208-1'