asterisk users - Nov 2005 - H standard extension

Hi,

Does anyone know if something like H standard extension exists in
Asterisk (I'm not talking about h standard extension). If yes what
does it do and what is the difference in comparison to h standard
extension.

One more thing; when I put h extension in my dial plan:

exten => h,1,SetVar(foo=${CHANNEL}) and someone hangs up the "foo"
consist the channel name from the phone which initialize the call. I
need to have the information about the channel of the phone which
answers the call.

Does anyone know where this information is stored?

Thanks in advance

Cheers