I was able to resolve the issue on my own. Here is the code sample for reference if anyone else is having similar issue.
LOOP AT gt_output INTO gw_output.
REFRESH bdcdata.
CLEAR bdcdata.
PERFORM bdc_dynpro USING 'SAPMV45A' '0102'.
PERFORM bdc_field USING 'BDC_CURSOR' 'VBAK-VBELN'.
PERFORM bdc_field USING 'VBAK-VBELN' gw_output-vbeln.
PERFORM bdc_field USING 'BDC_OKCODE' '/00'.
PERFORM bdc_dynpro USING 'SAPMV45A' '4001'.
PERFORM bdc_field USING 'BDC_OKCODE' '=HEAD'.
PERFORM bdc_field USING 'BDC_SUBSCR' 'SAPMV45A'.
PERFORM bdc_field USING 'BDC_SUBSCR' 'SAPMV45A'.
PERFORM bdc_field USING 'BDC_SUBSCR' 'SAPMV45A'.
PERFORM bdc_field USING 'BDC_SUBSCR' 'SAPLV45W'.
PERFORM bdc_field USING 'BDC_SUBSCR' 'SAPMV45A'.
PERFORM bdc_field USING 'BDC_CURSOR' 'VBAP-ZWERT(02)'.
PERFORM bdc_field USING 'BDC_SUBSCR' 'SAPMV45A'.
PERFORM bdc_dynpro USING 'SAPMV45A' '4002'.
PERFORM bdc_field USING 'BDC_OKCODE' '=T\06'.
PERFORM bdc_field USING 'BDC_SUBSCR' 'SAPMV45A'.
PERFORM bdc_field USING 'BDC_SUBSCR' 'SAPMV45A'.
PERFORM bdc_field USING 'BDC_CURSOR' 'VBAK-AUDAT'.
PERFORM bdc_dynpro USING 'SAPMV45A' '5002'.
PERFORM bdc_field USING 'BDC_OKCODE' '=V69A_KONX'.
PERFORM bdc_field USING 'BDC_SUBSCR' 'SAPMV45A'.
PERFORM bdc_field USING 'BDC_SUBSCR' 'SAPLV69A'.
PERFORM bdc_field USING 'BDC_CURSOR' 'KOMV-KSCHL(01)'.
PERFORM bdc_field USING 'BDC_SUBSCR' 'SAPLV69A'.
PERFORM bdc_dynpro USING 'SAPMSSY0' '0120'.
PERFORM bdc_field USING 'BDC_CURSOR' '04/03'. "1st place
PERFORM bdc_field USING 'BDC_CURSOR' '05/03'. "2nd place
PERFORM bdc_field USING 'BDC_CURSOR' '06/03'.
PERFORM bdc_field USING 'BDC_OKCODE' '=ENTR'.
PERFORM bdc_dynpro USING 'SAPMV45A' '5002'.
PERFORM bdc_field USING 'BDC_OKCODE' '=SICH'.
PERFORM bdc_field USING 'BDC_SUBSCR' 'SAPMV45A'.
PERFORM bdc_field USING 'BDC_SUBSCR' 'SAPLV69A'.
PERFORM bdc_field USING 'BDC_CURSOR' 'KOMV-KSCHL(01)'.
PERFORM bdc_field USING 'BDC_SUBSCR' 'SAPLV69A'.
* PERFORM bdc_dynpro USING 'SAPMV45A' '0102'.
* PERFORM bdc_field USING 'BDC_CURSOR' '/EBAC1'.
opt-racommit = 'X'.
CALL TRANSACTION 'VA42' USING bdcdata
* MODE 'A'
* UPDATE 'S'
MESSAGES INTO messtab
OPTIONS FROM opt.