Hi there,

At the moment the ExcelExportable trait does not have that option yet but you could get it from changing the columns' order before saving to the datastore like this:

->pipe(new \koolreport\processes\Map(array(
    '{meta}' => function($meta) {
        $exportedColumns = ['column2', 'column3', 'column1', 'column0'];
        $newMeta = ['columns' => []];
        foreach ($exportedColumns as $col)
            $newMeta['columns'][$col] = $meta['columns']['col'];
        return $newMeta;
    },
)))
->pipe($this->dataStore('exportedDatastore1'));

If this doesn't work for you, please send an email to support@koolphp.net, we will send you the latest version of ExcelExport.php. Thanks!