setting up layered navigation template from catalog.xml

Question

I am trying to set up the root template of <catalog_category_layered> from catalog.xml

I know how to use admin to change the root template for categories, but i want to change it from 'catalog.xml'. I added

<reference name="root">
            <action method="setTemplate"><template>page/product_view_custom.phtml</template></action>
</reference>

in <catalog_category_layered> just after the node starts. But it is not taking that template.

EDIT: IS the final say which layout is to be loaded for a category page is decided by magento admin? I guess YES.

If YES is there any way i can hard code my required layout to magento. Even if it means editing the core file i don't mind as this is for a internal beta release of an existing website. Why I am trying to do this is if i change anything in Admin it screws the live site

NOTE : The answer below was accepted as my question was slightly different initially. and for that it works fine.

Answer 1

Try and add the template overwrite to your templates local.xml

<?xml version="1.0"?>
<layout version="0.1.0">
   <catalog_category_layered>
      <reference name="root">
         <action method="setTemplate"><template>page/product_view_custom.phtml</template></action>
      </reference>
   </catalog_category_layered>
</layout>

[EDIT] Zamil pointed out he also requested a way of overwriting the Category layout updates and provided the solution for this. In my opinion this should be done by overwriting the controller from a custom extension but can be done by copying the CategoryController.php to app/code/local/Mage/Catalog/controllers/ and commenting out the following on line 149

$this->getLayout()->helper('page/layout')->applyTemplate($settings->getPageLayo‌​ut());