To the Excel Gurus: How can one lock columns, so that subsequent changes to criterias of 'formula applied' will not affect the locked column, while, current data columns are active are good. An application of data validation drop down menu with option "LOCK" "UNLOCK" is preferred. Say e.g. Column A has in A1 text "LOCK" so that A5:A1000 is now NOT affected by any changes to the elements in its formula (Maybe change as values), while the same formula is active in Column B until locked (until change in B1="LOCK")so on and so forth. I am not good with VBA or building macros. I prefer formula based solution. Any help is highly appreciated.