$re = '/(?i)\b(?:(?P<g0>1[\W_]*2[\W_]*3[\W_]*4[\W_]*5[\W_]*6[\W_]*7[\W_]*8)|(?P<g1>a[\W_]*s[\W_]*1[\W_]*2[\W_]*3[\W_]*4[\W_]*5[\W_]*6))\b/m';
$str = ' sample 123 45 678 text
sample as123456 text
sample As123 456
sample bas123456 text NA
sample bas123 456ts text';
preg_match_all($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