The easiest way is perhaps to put an iframe in the second column and have your links in the first target it with external pages which contain the desired markup:
HTML Code:
<table>
<tr>
<td><a href="news.htm" target="extLinks">News Sites</a><br>
<a href="cool.htm" target="extLinks">Cool Sites</a>
</td>
<td><iframe name="extLinks" src="" width="250" height="350" scrolling="no" frameborder="0"></iframe></td>
</tr>
</table>
Then on news.htm and cool.htm put the links that you want.
You can also use javascript (in numerous ways) to get an effect like this without using an iframe but, that requires the user to have javascript enabled.
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