What you would do:
in showflat.php you have to modify the query where all the posts are gathered from the database to include the Group each user is in. Then also modify the (list() to gather these groups to a variable.
Then, you have to make a check, whether the user is in your helo group , and whether his status is not admin or mod.
If the above conditions are met, asign a variable $postrow[$i]['Helo2image'] the image url, and then include this varaible in your showflat.tmpl file where you want the image to appear.
