Example of how to change all the values in the CSV report to upper case

example.php

<?php //Please do not include the opening PHP tag if you already have one.

function tw_ee_espresso_reg_report_filter_columns_strtoupper( $csv_row){
	foreach($csv_row as $key => $value) {
		$csv_row[$key] = strtoupper($value);
	}
	return $csv_row;
}
add_filter( 'FHEE__EventEspressoBatchRequest__JobHandlers__RegistrationsReport__reg_csv_array', 'tw_ee_espresso_reg_report_filter_columns_strtoupper', 999, 1);