Hello Sandeep,
To answer precisely to your question, you can do this with implicit enhancement in include LIBAPI_HF50 , with a code (at line no.138) such as:
if 1 = 0.
message e243(i0) with iv_proid ls_prps-werks cs_caufvd-iwerk.
endif.
But this should not be done.
Instead your checks for this field can be very easily managed through a simple code in user-exit IWO10009. You can get it done by your ABAPer, or if you give the logic, I'll provide the code to be put in the include ZXWOCU07 of this exit.
BTW you have several open threads (almost all). Please review and take them to logical conclusion.
Regards
KJogeswaraRao