// Format column as percentage
$sheet->setColumnFormat(array(
'C' => '0%'
));
// Format a range with e.g. leading zeros
$sheet->setColumnFormat(array(
'A2:K2' => '0000'
));
// Set multiple column formats
$sheet->setColumnFormat(array(
'B' => '0',
'D' => '0.00',
'F' => '@',
'F' => 'yyyy-mm-dd',
));
PHPExcel_Style_NumberFormat::FORMAT_GENERAL
PHPExcel_Style_NumberFormat::FORMAT_TEXT
...