[Exim] setting up autoresponders

Hi,

How do I go about setting up an autoresponder for a particular email
alias? I know i need to uncomment the auto-reply stuff form the
config... but Im not sure what to do after that... eg.. how do i specify
which address the auto responder is to respond to and how do i set up
the auto respond message?

I know this is prolly very easy but I couldnt find a solution in the FAQ.

Thanks

Mr P