Adding fields to customer order page

[Guest gadg3t shop]

Hi. i am wondering if the following is at all possible, I have searched the forums but found nothing that could help. Basically what i would like to do is when a customer places an order and you get the order page i would like to add a new box in there with a button, in the box i would like to place the order tracking number from our supplier and when the button is pressed this would put that number on the end of a website address i.e order tracking number = 1234 so the address would be www.abc123.com/1234 and then it would open this page. This would be for our reference only.

Any help would be really appreciated

Many thanks in advance