Extra information to the order and into the mail

[E.D.]

I creating a module now. I need a section which add an extra information to order and the sended mail (payment).

 

So:

- I go to the admin page (orders)

- I select an order

- I change the order status

- The module generate a random number

- The module save the number to order

- The module insert the number to the mail (example: payment)

 

I can catch the status update:

public function hookpostUpdateOrderStatus($params)...

 

But How could I save the number to order? And how I could insert into the mail???

 

Please Help Me...

 

PrestaShop 1.5.2.0

[E.D.]

Any idea?