Fijate si algo así te sirve:
Código PHP:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>test</title>
<style>
#pp{width:252px; height:59px;background:url(images/lg_Clarin.gif) -5px -20px no-repeat;}
</style>
</head>
<body>
<div id="pp"></div>
<script>
try{
//ie || w3c compat
r= document.styleSheets[0].rules || document.styleSheets[0].cssRules;
for (i=0; r.length; i++)
if (r[i].selectorText.toLowerCase() == '#pp'.toLowerCase()){
bg=r[i].style['background'].split(' ');
ret={left:bg[bg.length-2],top:bg[bg.length-1]};
alert(ret.left);
alert(ret.top);
}
}catch(e){}
</script>
</body>
</html>