Finding wrapper text using html

I have the following HTML code:

<div id="Test">
  My selected Link
  <a href="link1.html">My Link 1</a>
  <a href="link2.html">My Link 2</a>
</div>

      

        
        
        
      

    

I need to find a text string inside

<div id="Test"></div>

and wrap it with a tag. It will always only have one text line inside

<div id="Test"></div>

,

but the text will have different places in the code, for example:

<div id="Test">
  <a href="link1.html">My Link 1</a>
    Another Selected Link
  <a href="link2.html">My Link 2</a>
</div>

      

        
        
        
      

    

The result I'm looking for looks something like this:

<div id="Test">
  <a href="link1.html">My Link 1</a>
   <h2>Another Selected Link</h2>
  <a href="link2.html">My Link 2</a>
</div>

      

        
        
        
      

    

So to summarize: find a single text line inside the div (but not in the children tags) and wrap it with a tag.

Many thanks!