ExcelWorkSheet1.Cells.Item[0,0].Value:=标题; 报错，为何？有源码。(20分)

我用的是delphi6的控件：
procedure TfrmFindPrint.Button7Click(Sender: TObject);
var
ExcelApp1: TExcelApplication;
ExcelWorkbook1: TExcelWorkbook;
ExcelWorkSheet1: TExcelWorksheet;
begin
try
ExcelApp := TExcelApplication.Create(Self);
ExcelWorkbook1 := TExcelWorkbook.Create(Self);
ExcelWorkSheet1 := TExcelWorksheet.Create(Self);
except
ShowMessage ('false,no setup Excel2000');
abort;
end;
if FileExists('D:/yyy_pragram/delphi_test/print_xls' + 'demo.xls') then try //ɾ³ý¶¯Ì¬Éú³ÉµÄtemp.xls
DeleteFile('D:/yyy_pragram/delphi_test/print_xls' + 'demo.xls');
except
end;
ExcelApp.Connect
ExcelApp.Workbooks.Add('D:/yyy_pragram/delphi_test/print_xls/demo.xls', 0);
ExcelWorkBook1.ConnectTo(ExcelApp.Workbooks[1]);
ExcelWorkSheet1.ConnectTo(ExcelWorkBook1.Sheets[1] as _WorkSheet);
ExcelApp.Visible[0]:=True;
ExcelApp.Caption := 'Microsoft Excel';
ExcelApp.Range['A1','A1'].ColumnWidth := 5;
ExcelWorkSheet1.Cells.Item[0,0].Value:=标题;
ExcelWorkBook1.SaveCopyAs('D:/yyy_pragram/delphi_test/print_xls' + 'demo.xls');
ExcelApp.Quit;
ExcelWorksheet1.Disconnect;
ExcelWorkbook1.Disconnect;
ExcelApp.Disconnect;
end;

为何无人回复，我这里的确报错！

报错内容：OLE error 800A03EC.

真是急！急！急！！为何没有人理睬我？

是分数太少了吗？我已经快没分了，本身自己是delphi初学者。

ExcelWorkSheet1.Cells.Item[1,1].Value:=标题;
不能是[0，0]

不是因为你的分少，可能大家都在忙吧。

我已经苦恼了一天了，谢谢你的帮忙！

同意晴的说法！
[8D]