$re = '/(?x)Required\sDate
__
(?<PartNo1>[a-zA-Z0-9-]*\s
[0-9.]+)
__
(?<PartNo2>[a-zA-Z0-9-]*\s
[0-9.]+)/m';
$str = '__Required Date__40X0343 1.00__C734X77G 2.00__Net Order:__Sales Tax:__Freight:__Order Total:__0.00 __0.00 __5,328.50 __5,328.50 __or by fax
';
preg_match_all($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