транзакцию не подскажу, а вот ФМ...
Цитата:
KAUF_ORDER_CREATE
 
Associated Function Group: KAUF 
Released Date: Not Released 
Pattern for FM KAUF_ORDER_CREATE - KAUF ORDER CREATE Associated Function Group: KAUF 
Released Date: Not Released 
CALL FUNCTION 'KAUF_ORDER_CREATE' "
* EXPORTING
*   i_auart = SPACE             " aufk-auart    Order type
*   i_aufnr = SPACE             " aufk-aufnr    Order number (in external number assignment)
*   i_autyp_erl = SPACE         "               Valid order types
*   i_dialog = SPACE            "               Dialog messages allowed (popups etc.)
*   i_matnr = SPACE             " afpo-matnr    Material number (only for CO production order)
*   i_orext =                   " orext         External model for order
*   i_refnr = SPACE             " aufk-refnr    Reference order
*   i_werks = SPACE             " aufk-werks    Plant (only for CO production order)
  IMPORTING
    e_afko =                    " afko          Order header (enhancement for CO production order)
    e_afpo =                    " afpo          Order item (only for CO production order)
    e_coas =                    " coas          Order header
    e_kauf =                    " kauf          Administrative data
    e_index =                   " kauf-auf_index  Order index
  EXCEPTIONS
    FOREIGN_LOCK = 1            "               Order locked
    ORDER_TYPE_NOT_VALID = 2    "               Invalid order type
    REFERENCE_NOT_VALID = 3     "               Invalid reference order
    WRONG_INPUT = 4             "               Incorrect input parameters
    NO_NUMBER_RANGE = 5         "               Order type has no number intervall
    .  "  KAUF_ORDER_CREATE
вообще ФМ для внутренних заказов, но выделенные параметры подсказывают мне, что может можно и СО прикрутить. Сам не пробовал, код не смотрел, будет желание поковыряйте.