Display groups

Hi,

I'm getting on quite well with Zend_Form now including my custom elements.

Unfortunately, a new question came up.

For style reasons, form design bases on

<fieldset>
  <div class="inner">
     <form> .... </form>
  </div>
</fieldset>

I now I can use display groups to create fieldsets but
a) is this the best possible way
and
b) if so, how could I use the display group decorator to show both a 
fieldset and a div. There are rare examples on display group decorators 
on the internet unfortunately :(

Hope you know an answer.

cheers,

Stephan