Возможна небольшая вариация через ДИВ
<style type="text/css">
<!--
.zn_fon_1{background-image: url(FON_1.GIF);background-repeat: no-repeat;}
.zn_fon_2{background-image: url(FON_2.GIF);background-repeat: no-repeat;}
.zn_fon_3{background-image: url(FON_3.GIF);background-repeat: no-repeat;}
.zn_metka_1{background-image: url(metka.png);background-repeat: no-repeat;background-position: 50px 50px;}
.zn_metka_2{background-image: url(metka.png);background-repeat: no-repeat;background-position: 50px 100px;}
.zn_metka_3{background-image: url(metka.png);background-repeat: no-repeat;background-position: 100px 50px;}
.zn_metka_4{background-image: url(metka.png);background-repeat: no-repeat;background-position: 70px 150px;}
.zn_metka_5{background-image: url(metka.png);background-repeat: no-repeat;background-position: 157px 210px;}
.zn_metka_6{background-image: url(metka.png);background-repeat: no-repeat;background-position: 38px 200px;}
#metka {
position: relative;
width:50px;
height:50px;
z-index:1;
top: 50px;
left: 150px;
}
-->
</style>
<table width="700" height="374" border="1" cellpadding="0" cellspacing="0">
<tr>
<td width="200">
<ul>
<li><a href="">фон_1_50_50</a></li>
<li><a href="">фон_1_50_100</a></li>
<li><a href="">фон_2_100_50</a></li>
<li><a href="">фон_2_70_150</a></li>
<li><a href="">фон_2_157_210</a></li>
<li><a href="">фон_3_38_200</a></li>
</ul>
</td>
<td width="500" align="left" valign="top" id="zn_fon"><div id="metka"><img src="metka.png"></div></td>
</tr>
</table>
может через него будет и проще