Thanks abalabo,
I see the hook for this function as well as others. Not sure why it did not notice them before. I did find some hooks in the core/lib/order.pdf file specifically $this->extensions->hk_ProcessData($this, 'build_order_data', $order_info);.
If I want to add data to the build_order_data function $order_info array, what would be the proper function name to use?
Thanks