Data source Enhancement

HI Gurus,

i am enhansing a data source 2LIS_11_VAITM , by adding 5 fields for my Backlog model , 2LIS_11_VAITM has already been enhansed be some one else for Booking model, so if i enhanse this data source by wirting code in cmod ,will it restrict the records send to the Booking model . my code is some this like this for the BACKLOG Model

if ( mc11vaitm-status <> 'c')

CHECK MC11VAITM-NETWR > VBRP-NETWR .

CHECK MC11VAITM-NETWR > CALLOFFAmount.

SELECT ETENR EDATU WMENG LIFSP FROM VBEP

INTO TABLE XVBEP

WHERE VBELN = P_VBELN

AND POSNR = P_POSNR.

DESCRIBE TABLE xvbep LINES sy-tfill.

IF sy-tfill > 0.

LOOP AT VBEP .

Hear i will populate my 5 values

VAL1 = ..

VAL2 = .

VAL3

VAL4

VAL5

ENDLOOP .

ELSE .

ONCE AGAIN I WILL POPULATE VALUIES

VAUE1 .... TO VALUE5 .

ENDIF.

ENDIF .