def convert_name_area(row_num_1, col_num_1, row_num_2, col_num_2) #:nodoc:
      range1       = ''
      range2       = ''
      row_col_only = false

      # Convert to A1 notation.
      col_char_1 = xl_col_to_name(col_num_1, 1)
      col_char_2 = xl_col_to_name(col_num_2, 1)
      row_char_1 = "$#{row_num_1 + 1}"
      row_char_2 = "$#{row_num_2 + 1}"

      # We need to handle some special cases that refer to rows or columns only.
      if row_num_1 == 0 and row_num_2 == ROW_MAX - 1
        range1       = col_char_1
        range2       = col_char_2
        row_col_only = true
      elsif col_num_1 == 0 and col_num_2 == COL_MAX - 1
        range1       = row_char_1
        range2       = row_char_2
        row_col_only = true
      else
        range1 = col_char_1 + row_char_1
        range2 = col_char_2 + row_char_2
      end

      # A repeated range is only written once (if it isn't a special case).
      if range1 == range2 && !row_col_only
        area = range1
      else
        area = "#{range1}:#{range2}"
      end

      # Build up the print area range "Sheet1!$A$1:$C$13".
      "#{quote_sheetname(@name)}!#{area}"
    end
def convert_name_area(row_num_1, col_num_1, row_num_2, col_num_2) #:nodoc:
      range1       = ''
      range2       = ''
      row_col_only = false

      # Convert to A1 notation.
      col_char_1 = xl_col_to_name(col_num_1, 1)
      col_char_2 = xl_col_to_name(col_num_2, 1)
      row_char_1 = "$#{row_num_1 + 1}"
      row_char_2 = "$#{row_num_2 + 1}"

      # We need to handle some special cases that refer to rows or columns only.
      if row_num_1 == 0 and row_num_2 == ROW_MAX - 1
        range1       = col_char_1
        range2       = col_char_2
        row_col_only = true
      elsif col_num_1 == 0 and col_num_2 == COL_MAX - 1
        range1       = row_char_1
        range2       = row_char_2
        row_col_only = true
      else
        range1 = col_char_1 + row_char_1
        range2 = col_char_2 + row_char_2
      end

      # A repeated range is only written once (if it isn't a special case).
      if range1 == range2 && !row_col_only
        area = range1
      else
        area = "#{range1}:#{range2}"
      end

      # Build up the print area range "Sheet1!$A$1:$C$13".
      "#{quote_sheetname(@name)}!#{area}"
    end
convert_name_area(first_row, first_col, last_row, last_col)

 Convert zero indexed rows and columns to the format required by worksheet
 named ranges, eg, "Sheet1!$A$1:$C$13".