Try with below,
V_VALUE = ' ABC DEFG HIJK JKLM NOPQ RST'.
FIND REGEX '\bRST\b' IN V_VALUE.
IF SY-SUBRC = 0.
WRITE 'matched'.
ENDIF.
Hope this helps.
Try with below,
V_VALUE = ' ABC DEFG HIJK JKLM NOPQ RST'.
FIND REGEX '\bRST\b' IN V_VALUE.
IF SY-SUBRC = 0.
WRITE 'matched'.
ENDIF.
Hope this helps.