You can write a macro that will fire when you change the values in the cells. Private Sub Worksheet_Change(ByVal Target As Range). Indicate the range in which to track changes and then write the condition whether the cell in the specified range. If it does, drive one to the watches array, remove the second and insert the array data into the same range. Not only cycle, but how long will work. Copy and paste using Range.
PS. Macro to change cell values inserted into the module sheet.