<group id="cashondelivery" translate="label" type="text" sortOrder="30" showInDefault="1" showInWebsite="1" showInStore="1">
<label>Cash On Delivery Payment</label>
 ----
<field id="order_status" translate="label" type="select" sortOrder="20" showInDefault="1" showInWebsite="1" showInStore="0" canRestore="1">
     <label>New Order Status</label>
      <source_model>MagentoSalesModelConfigSourceOrderStatusNewprocessing</source_model>
OR
<source_model>MagentoSalesModelConfigSourceOrderStatus</source_model>
                </field>
---
</group>

<cashondelivery>
   <active>0</active>
   <model>MagentoOfflinePaymentsModelCashondelivery</model>
   <order_status>processing</order_status>
   <title>Cash On Delivery</title>
   <allowspecific>0</allowspecific>
   <group>offline</group>
</cashondelivery>