$re = '/(\b(ZVSEBACT|ZVSEBADD)[A-Z,0-9]{2}\.PACS_\.0230\.)(.*?)\.EBA\.(S202(SCT|COR))([A-Z,0-9]{8})(?=\.I\b)/m';
$str = 'ZVSEBACTAA.PACS_.0230.[YYYYMMDDhhmmss].[Q5].EBA.S202SCTAAAAAAAA.I ZVSEBADD11.PACS_.0230.[YYYYMMDDhhmmss].[Q5].EBA.S202COR11111111.I';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php