asterisk users - Feb 2013 - record filename + extension

When recording the filename I use:
exten =>
_NXXXXXX,n,Set(recordfilename=${EXTEN}-${STRFTIME(${EPOCH},MST,%C%y_%m_%d_%H%M)}.wav)

This works OK but I would like to add to the name the local extension from which
the calls is originating, what is the variable called?

-- 
Joseph

On Friday 01 February 2013, Joseph wrote:
> When recording the filename I use:
> exten =>
> _NXXXXXX,n,Set(recordfilename=${EXTEN}-${STRFTIME(${EPOCH},MST,%C%y_%m_%d_
> %H%M)}.wav)
> 
> This works OK but I would like to add to the name the local extension from
> which the calls is originating, what is the variable called?
${CALLERID(num)} has the originating extension number, unless you changed it 
e.g. to show your direct line on an outgoing call  (but you can always do that 
*after* you generate the filename for the recording).

-- 
AJS

Answers come *after* questions.