Customer Line Item from Billing Document

Dear Experts,

I am PS Consultant.

Request you to give your expert advise on the following...

I need to add two additional line item through exit as mentioned in SAP Note 301077 - User exits for the interface for accounting.

1) 09 (PK) D (SGL Ind.) 100000 (Account - Customer) - Dr. 1000

2) 16 (PK)                     100000 (Account - Customer) - Cr. 1000

Kindly let me know the exit to be used from the note 301077 and the logic.

Thanks

Abdul