You know when delay is 0 the message will be sent next dailymail.  I believe you are asking if there is a way to see when "Cron-style Followups" are due to be sent - is that right?  Currently this is not possible and it would take a fair custom script to achieve it.  You can find the code in the dailymail.php file...
 include('./cron.php');
  $cr = new cron;
  $now = date("Ymd",time());
         while(list($mid,$cron)=mysql_fetch_row($result5)){
          if($cron){
           $cr->calcLastRan("* * ".$cron);
           $due = date("Ymd",$cr->getLastRanUnix()-1);
           if($now == $due){
            $sendids[] = $mid;
            if($DEBUG) echo " Delay is 0 and cron is due on the new message - sending!<br>";
           }
          }
If you know PHP you could create a script to look ahead a number of days and run the cron test for each followup...  This could further be cross-referenced with users, but it is definitely a non-trivial job!
Regards