<?php

// Matches one of " * : % $ / \ ' ?
$patternOne = '#["*:%$/\\\\\'?]#';

// Desired: matches one of " * : % $ / \ ' ?, but ALLOWS {DATE:.*?}
$patternTwo = '#["*:%$/\\\\\'?](?<!{DATE:)#';
$record = [];
$record['filenameGood'] = '49161_Comma_Dataphoria-Clickwork7Export{DATE:dmY}';
$record['filenameBad'] = '49161_Comma_Dataphoria-Clickwork7:Export{DATE:dmY}';

var_dump(preg_match($patternTwo, $record['filenameGood']));
var_dump(preg_match($patternTwo, $record['filenameBad']));