$cc = new File_Convert($targetTmp,'application/vnd.ms-excel');
$targetTmp = $cc->convert('application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');
$cc = new File_Convert($targetTmp,'application/vnd.ms-excel');
$targetTmp = $cc->convert('application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');