Creating Commercial Invoice

Hi All ,

I have a business requirement ,With reference to proforma invoice , Export Invoice  ..... the business  requires to create a Invoice Document called Commercial Invoice .

its 1 to 1 &  Many to 1 .

I have tried  but unable to  fetch the desired results .

This commercial Invoice is used for Export Clearing  .  The Commercial Invoice will not have any  impact on accounting   Entries .

Could Any One guide  on  how to meet the  above requirement !