[asterisk-users] how can I detect a DTMF tone while on a bridged call ? anyone knows?

[MF]

Hi all

I have a call that comes in via a first E1  and goes out via a second 
one,  my problem is I need to catch a digit dialed by the second one,  
during the conversation,  I know I can detect the # for a call 
transfer,  but nothing else, 

Any Idea on how to do this I deeply appreciate, !!

thanks