Billing document creation without any refrence

Hi,

  I need to create billing document without any reference ( Sales order & delivery ).  I have found one BAPI ( BAPI_BILLINGDOC_CREATEFROMDATA ) Its working fine for me. But it is worked for single line item. If the billing document having more than one line item means, how to pass condition type like ( PR00 ).

How to reduce stock for the billed material quantity.

Thanks & Regards,

Partha