Hello Ankesh,
Modify MARC segment after MVKE is filled.
Please find the below sample code :-
Loop at IDOC_DATA into WA_ IDOC_DATA .
case wa_idoc_data-SEGNAM.
when 'E1MVKEM'
READ TABLE IDOC_DATA into WA_ido WITH KEY segname = E1MARCM
if sy-subrc = 0.
*write your logic here and modify idoc_data
endif.
endcase.
Endloop.
Thanks