I'd like DaDa to store the name of the list being edited in a cookie
so FCK can use that for user-specific file upload directories,
templates, etc I'm comfortable with PHP but It's been a long time
since I've done any Perl coding, and it was pretty basic then Any
pointers on the most elegant way to extend DaDa to include a new
cookie would be most welcome � thanks

Here's some ideas,

To just have Dada Mail store a new cookie, you can try tweaking the
login subroutine in the mail cgi file Here's the lines to look for:

         print $q->header(-cookie  => [$dumb_cookie, $login_cookie],
                           -nph     => $DADA::Config::NPH,
                           -Refresh =>'0; URL=' 
 $referer);

You can just add another cookie to the end of that, like this:

    my $fckeditor_cookie = $q->cookie(
                -name => 'dada_mail_list',
                -value => $admin_list,
                %DADA::Config::COOKIE_PARAMS,
               );

         print $q->header(-cookie  => [$dumb_cookie,  

$login_cookie, $fckeditor_cookie], -nph => $DADA::Config::NPH, -Refresh =>'0; URL=' $referer);

Then, just make sure to clear it out when you're done, find these
lines the logout subroutine, also in the mail cgi file:

     print $q->header(-COOKIE       => $logout_cookie,
                           -nph     => $DADA::Config::NPH,
                           -Refresh =>'0; URL=' 
 $location,
                         );

and just add another cookie with no real value:

    my $fckeditor_cookie = $q->cookie(
                -name => 'dada_mail_list',
                -value => undef,
                %DADA::Config::COOKIE_PARAMS,
               );

     print $q->header(-COOKIE       => [$logout_cookie,  

$fckeditor_cookie], -nph => $DADA::Config::NPH, -Refresh =>'0; URL=' $location, )

If you do a little test:

#!/usr/bin/perl -w
use strict;
use CGI;
my $q = new CGI;

my $fckeditor_cookie = $q->cookie(
            -name => 'dada_mail_list',
            -value => 'mylist',
    );
print $q->header(-cookie  => [$fckeditor_cookie]);

Looks like the headers return looks something like this:

Set-Cookie: dada_mail_list=mylist; path=/
Date: Tue, 09 Dec 2008 02:34:27 GMT
Content-Type: text/html; charset=ISO-8859-1

So, that looks easy enough to parse out