Click the file preview and set the markers against the ruler to
               define the file column properties. The orange arrow helps you refine the
               position.
            
            The Field Separator and
                  Marker Position fields are automatically
               filled with a series of figures separated by commas.
            The figures in the Field
                  Separator are the number of characters between the separators, which
               represent the lengths of the columns of the loaded file. The asterisk symbol means
               all remaining characters on the row, starting from the preceding marker position. You
               can change the figures to specify the column lengths precisely.
            The Marker Position field
               shows the exact position of each marker on the ruler, in units of characters. You can
               change the figures to specify the positions precisely.
            To move a marker, press its arrow and drag it to the new position. To remove a
               marker, press its arrow and drag it towards the ruler until a 

 icon appears.