[Lynne]

OK, here's the default:

PHP Code:

$stylevar[dirmark]<a href="member.php?$session[sessionurl]u=$loggedin[userid]">$loggedin[musername]</a>$loggedin[invisiblemark]$loggedin[buddymark] 


So, perhaps try:

PHP Code:

$stylevar[dirmark]<a href="member.php?$session[sessionurl]u=$loggedin[userid]">$loggedin[musername]</a>$loggedin[invisiblemark]<if condition="$loggedin[buddymark]=='+'"><img src="path/to/image/folder/yourimage.jpg" width="xx" height="yy" alt="Buddy" border="0"></if> 


I haven't tested that, but I think it should work.