uses AciveX;        // для Delphi 3 и 4

uses Ole2, OleAuto; // для Delphi 2

procedure TForm1.Button1Click(Sender: TObject);
var 
  MyExcel: Variant;
begin
  MyExcel:=CreateOleObject('Excel.Application');
  MyExcel.Visible:=true;
  MyExcel.WorkBooks.Add;
  MyExcel.Cells[1,1].value:='1';
  MyExcel.ActiveWorkbook.SaveAs(PATHNAME);
  MyExcel.Quit;
end;