How to pass the data to accounting document header from sales document?

The information in the below three fields is available in Sales Document. We should
copy the information from sales document and passed to accounting.

1.sales document

2.sold to country of customer

3.commision agent

Mapping:

          Vf01/vf02/vf03                      va03

1. Document Header Text - Sold to country of Customer
2. Reference key(head1) - Commission Agent(Dealer)
3. Reference key(head2) – Sales Manager

I need exit name in which i need to add the three fields.