Hello Sanjana,
This is the code which is working.
IF CAUFVD_IMP-GLUZP = '000000'. CAUFVD_IMP-GLUZP = '240000'. CALL FUNCTION 'CO_IH_SET_HEADER' EXPORTING CAUFVD_IMP = CAUFVD_IMP IMPORTING CAUFVD_EXP = CAUFVD_IMP. PERFORM HEADER_UPDATE(SAPLCOIH). ENDIF.
Test well in Development clients 100,220 etc before you adapt it.
KJogeswaraRao