first line of message body in the maillist.html page ...

Hi;
        I would like to put, in the generated maillist.html  page,
non simply the subject, from, date fields of the mail message 
but also the first 200-300 characters of the mail message body ...
I didn't succed by myself, someone can help me?

there is a variable or I should try to "hack" one of the
perl scripts of mhonarc? and which one?

Many thanks
        Gabriele Elia