Exportar consulta SQL para Excel

Olá, gente.O problema é o seguinte: tenho o código abaixo para, de acordo com uma consulta SQL ser gerado uma planilha do Excel. Só que, na hora de salvar aparece uma mensagem: O método SaveAs da classe Workbook falhou.Alguém pode me dar uma ajuda, por favor?
procedure TfmConsultaRPS.ExportarXLS;var  vExcel : Variant;  iLinha : Integer;  sData,  sNomeDoArquivo : string;begin  sData          := DateToStr(Date);  sNomeDoArquivo := Copy(sData,1,2) + '-' +                    Copy(sData,4,2) + '-' +                    Copy(sData,7,4) + '_' +                    RetiraChar(TimeToStr(Now),':')  +                    '.xls';  vExcel         := CreateOleObject('Excel.Application');  vExcel.Visible := False;  vExcel.Workbooks.Add;  //Criando a primeira linha (Cabeçalho)  vExcel.WorkBooks[1].Sheets[1].Cells[1, 1] := 'CPF';  vExcel.WorkBooks[1].Sheets[1].Cells[1, 2] := 'N.RPS';  vExcel.WorkBooks[1].Sheets[1].Cells[1, 3] := 'Referência';  vExcel.WorkBooks[1].Sheets[1].Cells[1, 4] := 'Dt. Emissão';  vExcel.WorkBooks[1].Sheets[1].Cells[1, 5] := 'Dt. Vencimento';  vExcel.WorkBooks[1].Sheets[1].Cells[1, 6] := 'Nome do Aluno';  vExcel.WorkBooks[1].Sheets[1].Cells[1, 7] := 'Nome do Responsável';  vExcel.WorkBooks[1].Sheets[1].Cells[1, 8] := 'CPF';  vExcel.WorkBooks[1].Sheets[1].Cells[1, 9] := 'CEP';  vExcel.WorkBooks[1].Sheets[1].Cells[1,10] := 'Logradouro';  vExcel.WorkBooks[1].Sheets[1].Cells[1,11] := 'Nº';  vExcel.WorkBooks[1].Sheets[1].Cells[1,12] := 'Complemento';  vExcel.WorkBooks[1].Sheets[1].Cells[1,13] := 'Bairro';  vExcel.WorkBooks[1].Sheets[1].Cells[1,14] := 'Cidade';  vExcel.WorkBooks[1].Sheets[1].Cells[1,15] := 'UF';  vExcel.WorkBooks[1].Sheets[1].Cells[1,16] := 'Valor a Pagar';  vExcel.WorkBooks[1].Sheets[1].Cells[1,17] := 'Valor Após Vencimento';  vExcel.WorkBooks[1].Sheets[1].Cells[1,18] := 'Desconto';  vExcel.WorkBooks[1].Sheets[1].Cells[1,19] := 'Valor IRRF';  vExcel.WorkBooks[1].Sheets[1].Cells[1,20] := 'Base Cálc. ISS';  vExcel.WorkBooks[1].Sheets[1].Cells[1,21] := 'Alíquota ISS';  vExcel.WorkBooks[1].Sheets[1].Cells[1,22] := 'Valor ISS';  vExcel.WorkBooks[1].Sheets[1].Cells[1,23] := 'E-Mail';  vExcel.WorkBooks[1].Sheets[1].Cells[1,24] := 'Cód. Serviço';  //vExcel.WorkBooks[1].Sheets[1].Cells[1,2] := 'N.RPS';
  iLinha := 2; //Passando para a segunda linha  with dmEmissor_NFs, qryConsulta do  begin    while not Eof do    begin      vExcel.WorkBooks[1].Sheets[1].Cells[iLinha, 1] := FieldByName('NFPRESTADOR').AsString;      vExcel.WorkBooks[1].Sheets[1].Cells[iLinha, 2] := FieldByName('NUMNF').AsString;      vExcel.WorkBooks[1].Sheets[1].Cells[iLinha, 3] := FieldByName('NFREFERENCIA').AsString;      vExcel.WorkBooks[1].Sheets[1].Cells[iLinha, 4] := FieldByName('NFDTEMISSAO').AsString;      vExcel.WorkBooks[1].Sheets[1].Cells[iLinha, 5] := FieldByName('NFVENCIMENTO').AsString;      vExcel.WorkBooks[1].Sheets[1].Cells[iLinha, 6] := FieldByName('NFALUNO').AsString;      vExcel.WorkBooks[1].Sheets[1].Cells[iLinha, 7] := FieldByName('NFNOME').AsString;      vExcel.WorkBooks[1].Sheets[1].Cells[iLinha, 8] := FieldByName('NFCPF').AsString;      vExcel.WorkBooks[1].Sheets[1].Cells[iLinha, 9] := FieldByName('NFCEP').AsString;      vExcel.WorkBooks[1].Sheets[1].Cells[iLinha,10] := FieldByName('NFENDERECO').AsString;      vExcel.WorkBooks[1].Sheets[1].Cells[iLinha,11] := FieldByName('NFNUMERO').AsString;      vExcel.WorkBooks[1].Sheets[1].Cells[iLinha,12] := FieldByName('NFCOMPLEMENTO').AsString;      vExcel.WorkBooks[1].Sheets[1].Cells[iLinha,13] := FieldByName('NFBAIRRO').AsString;      vExcel.WorkBooks[1].Sheets[1].Cells[iLinha,14] := FieldByName('NFCIDADE').AsString;      vExcel.WorkBooks[1].Sheets[1].Cells[iLinha,15] := FieldByName('NFUF').AsString;      vExcel.WorkBooks[1].Sheets[1].Cells[iLinha,16] := FieldByName('NFVALOR').AsString;      //vExcel.WorkBooks[1].Sheets[1].Cells[iLinha,17] := FieldByName('NFREFERENCIA').AsString;      vExcel.WorkBooks[1].Sheets[1].Cells[iLinha,18] := FieldByName('NFDESCONTO').AsString;      vExcel.WorkBooks[1].Sheets[1].Cells[iLinha,19] := FieldByName('NFVALORIRRF').AsString;      vExcel.WorkBooks[1].Sheets[1].Cells[iLinha,20] := FieldByName('NFBCISS').AsString;      vExcel.WorkBooks[1].Sheets[1].Cells[iLinha,21] := FieldByName('NFALIQISS').AsString;      vExcel.WorkBooks[1].Sheets[1].Cells[iLinha,22] := FieldByName('NFVALORISS').AsString;      vExcel.WorkBooks[1].Sheets[1].Cells[iLinha,23] := FieldByName('NFEMAIL').AsString;      vExcel.WorkBooks[1].Sheets[1].Cells[iLinha,24] := FieldByName('NFCODSERVICO').AsString;      iLinha := iLinha + 1;      Next;    end;  end;  vExcel.WorkBooks[1].SaveAs(dredtPasta.Text + '\' + sNomeDoArquivo);  vExcel.WorkBooks[1].Close;  MsgInfo('O arquivo será salvo na pasta:' + #13 +          QuotedStr(dredtPasta.Text) + #13 +          'com o nome: ' + #13 +          QuotedStr(sNomeDoArquivo));
end;
Valeu.