Try this on a test forum first-
<script>
// created by celebrus of aetus.net
var mname="Member's display name";
var images[0]="http://url2imagebeforethename";
var images[1]="http://url2imageafterthename";
// not much editing needed after this.
if(typeof('$')== "undefined"){document.write('<script src="http://"+window.location.host+"/jquery.js" type=text/javascript></script>');}
var newname = images[0]+mname+images[1];
$("a:contains("+mname+")").text(newname);
</script>
I could base it on the user id if you want.