magento 1.9 – Help: Edit an order programmatically ( cancel old one and create new order with the increment ID as increment_id-x )

Please if anyone can help me, I’m trying to create a (Soap API v2 ) extension where I can edit an order programmatically, but I don’t know where to start !!

I tried to use the function startAction() on Mage_Adminhtml_Sales_Order_EditController, I even changed some code on the initFromOrder($order) on Mage_Adminhtml_Model_Sales_Order_Create but what happens is that I create another order based on the old one’s details. what I want is to cancel the old one and create a child order with the increment_id-x

I appreciate your help guys, and thanks a lot