Свойство Rows

With Workbook.Sheets[1].Range['A1', 'F10'] do begin
  Rows[2].Font.Bold := True;
end;

With Workbook.Sheets[1].Range['A1', 'F10'] do begin
  Rows[3].Value := Rows[2].Value;
end;

MessageDlg('The selection contains ' +
           inttostr(Workbook.Worksheets[1].Selection.Rows.Count) + ' rows.',
           mtInformation, [mbOk], 0);