I figured out how to find the screen spot where the clik happens.
So perhaps you can use it, or even enhance it.
This would show where on screen the mouse was cliked.
<table width="100" id="tabletest" border="0" cellpadding="1" cellspacing="1" bgcolor="#0000FF" onclick="alert(this.x);">
<tr>
<td bgcolor="#FFFFCC">test</td>
</tr>
</table>
Sorry, I coudn't find anything more concrete!
Hope this helps.