after another 30 minutes I have done the following and I came to the same conclusion than you
Archive.ss
<% if GetArchive %>
<div class="sidebarBox">
<h3>Sub Menu</h3>
<% control GetArchive %>
<p>$Title</p>
<% end_control %>
</div>
<% end_if %>
this is an include file to encapsulate it a little bit.
But is it possible to render the template from the controller level. Before this SilverStripe I have done mostly everything with Zend Framework and Silverstipes architecture is completely different to the Zend approach, thats why I am often a little bit confused how to do things in Silverstripe.
But anyway Silverstripe has some nice functions :)
Regards Thomas