ME52N: Purchase Requisition Change GL Account Number

Question

Requirement: ABAP auto-change the GL Account field number in a Purchase Requisition after the Material Group is changed.
Background: This custom logic has been successfully applied to all types of Purchase Requisitions using  BADI ME_PROC_REQ_CUST, with the exception of a Purchase Requisition type that is called a 'Service Limits'. There are differences that are important to note between a 'Service Limits' Purchase Requisition and the other Purchase Requisitions that had custom code added without any problems.
1)This type of Purchase Requisition uses a item category of 'B', and the logic has a tendency to flow through SAP differently.
2)This type of Purchase Requisition's GL Account number is under-intensified on the 'item' subscreen, and cannot be changed manually on that screen like the others..
3)In order for the GL Account to be changed manually, or for the GL Account to be changed once my code has changed the GL Account Number, the user must select the 'Limits' tab and select the Account Assignment arrow, then a popup appears where the GL Account can be changed manually, or, my coded GL Account number change then occurs.
Problem: I want the custom code to be able to change the GL Account NUmber without having to go into thge 'Limits' tab, where the icon has to be selected. I believe the problem is that the field is protected, because it displays as under-intensified, thus, preventing my new GL Account NUmber from displaying. I also have the subsequent SAP code below that appears to reject set_exkn because protect is set to 'X'.
CODE1: Is my custom code.
CODE2: Is the SAP code that my will flow into where this field appears to be unchangeable.
My question:
I am thinking that this GL Account field is protected and cannot be changed because it is under-intensified on the subscreen on the Purchase Requisition. Can it be changed with custom code, a way to 'unprotect it'? Or, are there settings that should be changed in SPRO for the Purchase Requisition to allow this functionality to change the GL Account number.
   Thank-You
(CODE1)
METHOD IF_EX_ME_PROCESS_REQ_CUST~PROCESS_HEADER.
*Purchase Requisition Item Declarations
  DATA: LT_ITEMS        TYPE MMPUR_REQUISITION_ITEMS.
  DATA: LS_ITEM         TYPE MEREQ_ITEM.
  FIELD-SYMBOLS: <FS_ITEM> TYPE LINE OF MMPUR_REQUISITION_ITEMS.
*Purchase Requisition Accounting Declarations.
  DATA: LT_ACCT         TYPE MMPUR_ACCOUNTING_LIST.
  DATA: LS_ACCT         TYPE EXKN.
  DATA: LS_SETX          TYPE MEPOACCOUNTING_DATAX.
  FIELD-SYMBOLS: <FS_ACCT> TYPE LINE OF MMPUR_ACCOUNTING_LIST.
  CALL METHOD IM_HEADER->GET_ITEMS
    RECEIVING
      RE_ITEMS = LT_ITEMS.
  LOOP AT LT_ITEMS ASSIGNING <FS_ITEM>.
    LS_ITEM = <FS_ITEM>-ITEM->GET_DATA( ).
    LT_ACCT = <FS_ITEM>-ITEM->IF_ACCT_CONTAINER_MM~GET_ITEMS( ).
    LOOP AT LT_ACCT  ASSIGNING <FS_ACCT>.
      LS_ACCT =  <FS_ACCT>-MODEL->GET_EXKN( ).
      LS_ACCT-SAKTO = 'N500300   '.
      LS_SETX-SAKTO = 'X'.
      <FS_ACCT>-MODEL->SET_EXKN( LS_ACCT ).
      <FS_ACCT>-MODEL->SET_EXKNX( LS_SETX ).
    ENDLOOP.
  ENDLOOP.
ENDMETHOD.
(CODE2)
METHOD if_accounting_model_mm~set_exkn.
  DATA: ls_buffer     LIKE LINE OF my_data_input_buffer,
        ls_bufferx    LIKE LINE OF my_data_input_bufferx,
        l_buffered    TYPE sy-subrc,
        l_data_old    TYPE exkn,
        l_data_oldx   TYPE mepoaccounting_datax,
        l_data_newx   TYPE mepoaccounting_datax,
        l_indx        TYPE sy-tabix.      "1478013
  *PROTECT EQ 'X'
  CHECK my_state->protect EQ mmpur_no.
Edited by: Tom Matys on Dec 12, 2011 10:55 AM

Answer 1

Your PO release strategy must have been based on Cost Center as one of characteristics.
Pl check & confirm.
Regards
Bhavesh Mistry