$re = '/Vol=.*\(([\d,.]+)\).*\(([\d,.]+)\).*\(([\d,.]+)\).*\(([\d,.]+)\).*\(([\d,.]+)\).*\(([\d,.]+)\).*\(([\d,.]+)\).*\(([\d,.]+)\).*(?=,Drift)/';
$str = '"Interest.USD,Vol=[Integrated,(0,0.101),(0.2,0.108),(1,0.110),(2,0.106),(3,0.102),(4,0.09),(5,0.091),(6,0.09128272)],Drift=[Integrated,(0.002,0.09),(0.24,0.0007),(0.4,0.007),(1,-0.033),(2,-0.005),(3,-0.0041),(4,-0.3505),(5,-0.65),(7,-0.08346),(8,-0.049),(9,-0.0613),(10,-0.019)],Risk_Neutral=YES,Lambda=0.09,FX_Volatility=0.01,FX_Correlation=0.9"
';
preg_match($re, $str, $matches, PREG_OFFSET_CAPTURE, 0);
// Print the entire match result
var_dump($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