show information of one-time customer in Cover letter

Hi Experts,

Here is my situation, I used one-time customer to create oders, when a widow that require the detail of the customer poped up, I entered some information(city,street, etc) of the customer.

When I generate automatic report shipping, in the cover letter, I found the infor I entered during creating orders did not shown, instead, the infor showed in the cover still use infor that stored in customer master table KNA1.

I checked the cover sheet template in CG4B and found the part where show address infor of the customer is defined by report symbols, and the function module that controll the logic of the report symbol is getting record from table KNA1, I want to change the logic of the FM, but do not know how I could get the document number of the order that I created.

Could you please help me with this?

How could I make the infor of the customer that I entered when creating order be shown in the cover letter?

Many thanks for all your help!

Anna