title: Pass variable from inline block to template file in magento
body: <p>I have in the magento home content </p>
  
  <pre><code>{{block type="catalog/navigation" template="catalog/navigation/sub_navigation.phtml"}}
  </code></pre>
  
  <p>This is calling a set of subcategorys of the given parent category ID.
  Now I want to influence my <code>$parent_category</code> already from this given block. I found <a href="https://stackoverflow.com/questions/13194117/how-to-pass-variable-from-block-to-phtml-in-magento">How to pass variable from block to phtml in magento</a> but they don't show the same way of notation. 
  How to integrate the <code>setData</code> action into the given block notation?
  Thanks for your help!</p>