[Eng]

el user exit que te hace eso es el siguiente.
si esta aplicada la siguiente nota 329898
EXIT_SAPLEBND_002
si no esta aplicada.
CUSTOMER-FUNCTION '002'

recibes 2 estructuras
I_CEKKO datos de cabecera de factura, recibe user exit
E_CEKKO datos de cabecera de factura, es la estructura k devuelve el user exit
IT_BEKPO tabla interna con todas las posiciondes del pedido.

te anexo el programa standar donde se encuentra
MM06EF0S
*-----------------------------------------------------------------------
*- Änderungen:
*- HinwNr Datum Rel. Autor Text
*- 82583 03.09.97 31I TS me59, Umlagerung: keine Kalk.schemaermitt
* 83917 15.10.1997 3.1I GT : Löschen Streckenpos. Bestellwert fakturier

*eject
************************************************************************
* *
* Unterroutinen Bestellabwicklung *
* Routinen alphabetisch geordnet; hier beginnend mit "S" *
* *
************************************************************************

INCLUDE MM06EF0S_SEPO_FUELLEN . " SEPO_FUELLEN

INCLUDE MM06EF0S_SD_AEND_VORBEREITEN . " SD_AEND_VORBEREITEN

INCLUDE MM06EF0S_SD_FLUSS_VORBEREITEN . " SD_FLUSS_VORBEREITEN


INCLUDE MM06EF0S_SD_CHECK_LOEKZ . " SD_CHECK_LOEKZ

INCLUDE MM06EF0S_STAMM_BANF . " STAMM_BANF

INCLUDE MM06EF0S_STAMM_BESTAND . " STAMM_BESTAND

INCLUDE MM06EF0S_STAMM_INFOSATZ . " STAMM_INFOSATZ

INCLUDE MM06EF0S_STAMM_LIEFERANT . " STAMM_LIEFERANT

INCLUDE MM06EF0S_STAMM_MATERIAL . " STAMM_MATERIAL

INCLUDE MM06EF0S_STAMM_ORDERBUCH . " STAMM_ORDERBUCH


INCLUDE MM06EF0S_STAMM_QUOTIERUNG . " STAMM_QUOTIERUNG

INCLUDE MM06EF0S_STATISTIK_VORBEREITEN . " STATISTIK_VORBEREITEN

INCLUDE MM06EF0S_STEUERSCHEMA . " STEUERSCHEMA

INCLUDE MM06EF0S_SCHEMA_SETZEN . " SCHEMA_SETZEN

INCLUDE MM06EF0S_STEUER_US . " STEUER_US

INCLUDE MM06EF0S_SET_VAKE_KOTABNR . " SET_VAKE_KOTABNR

INCLUDE MM06EF0S_STRATEGIE_ERMITTELN . " STRATEGIE_ERMITTELN aki se encuentra el user exit

INCLUDE MM06EF0S_STRATEGIE_CEKKO . " STRATEGIE_CEKKO
INCLUDE MM06EF0S_STRATEGIE_AEND_CHECK . " STRATEGIE_AEND_CHECK

INCLUDE MM06EF0S_SUBTRACT_BZTEK . " SUBTRACT_BZTEK

INCLUDE MM06EF0S_SLL_DOCUMENT_TRANSFER .

lee este articulo para que tengas una idea mas clara.

si gustas te mando el codigo de como lo implemente.