Regular Expressions help needed

[Andreas Klemt]

Hello,
I have this HTML

<a name=section1></a>
<a href="myurl1_1.thm">Link1_1</a>
<a href="myurl1_2.thm">Link1_2</a>
<a href="myurl1_3.thm">Link1_3</a>

<a name=section2></a>
<a href="myurl2_1.thm">Link2_1</a>
<a href="myurl2_2.thm">Link2_2</a>

<a name=section3></a>
<a href="myurl3_1.thm">Link3_1</a>
<a href="myurl3_2.thm">Link3_2</a>
</html>

I want to GROUP all Links from section1 and section3.
Can someone please show me how to do my Regular Expression?

I tried this but it didn't work:
<a name="section1">.*?<a.*?>(?<Link>[^<]*).*?<a name="section2"></a>.*?<a
name="section3">.*?<a.*?>(?<Link>[^<]*).*?</html>

Many thanks for any help in advance!!!
Andreas