$re = '/^[A-Z]{4,5}_((?![^_]*(?i:test))[^_]*)_\d{6}_\d_.{2}\d_.{2}$/m';
$str = 'ABCD_EFGHI-78-32#1-R77.2_301009_1_AB3_CD
ABCD_EFGHI-78-32#1-TEST-R77.2_301009_1_AB3_CD';
preg_match_all($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