DIAL App macro, READ caller digits

I am trying to all the caller to hangup on the callee by pressing **

I wrote this macro:

[macro-callhanguptest]
exten => s,1,wait(0.2)
exten => s,n,Set(TIMEOUT(digit)=60)
exten => s,n(start),read(hangupthis,,2)
exten => s,n,gotoif($["${hangupthis}" != "**"]?start)
exten => s,n,playback(hello-world)
exten => s,n,Set(MACRO_RESULT=CONTINUE)

;and it is called by this
[maincontext]
...
same => n,Dial(SIP/6305551212@flowroute,30,gM(callhanguptest))

My problem is the READ app in the macro only is listening on the CALLEE side, not the caller, how do I get that macro to listen to the Caller dtmf as well?

Thanks!!

I found out that in asterisk 10 it is “**” that hangs up if you use the H option. The docs on it were for 1.4, and I guess at that time it was just * that hung up.