I've gotten quite used to overwriting magento's frontend layout files, so I thought it would be easy to overwrite a phtml template in the admin panel - but I've gotten nowhere in the last six hours. All tutorials I've found so far are concentrating on creating a controller, but I only need to overwrite two phtml files since I only want to change the dispaly of the ordered items a little.
Specifically I want to overwrite the default/template/sales/order/view/items.phtml, normally i'd just match that path in my design folder of my own module and call it a day.
I can overwrite the block php file in Mage/Adminhtml/Sales/Order/View/Items.php through my config.xml:
<config>
...
<global>
...
<blocks>
...
<adminhtml>
<rewrite>
<sales_order_view_items>MyCompany_MyModule_Block_Adminhtml_Sales_Order_View_Items</sales_order_view_items>
</rewrite>
</adminhtml>
</blocks>
...
</global>
...
</config>
How can I tell Magento to use my phtml file in design/adminhtml//default/sales/order/view/items.phtml ?
Shouldn't these lines in my config.xml work?
<config>
...
<adminhtml>
<layout>
<updates>
<my_module>
<file>order_list.xml</file>
</my_module>
</updates>
</layout>
</adminhtml>
...
</config>
Any help is really appreciated! I really hope I've just overlooked something...