$re = '/\"--CVP.*(<sip:.*@.*)/';
$str = '"--CVP_11_5_1_0_1_0_349" <sip:05335816023@10.134.27.2>;tag=1417F2E5-2588
"Emre Sumengen" <sip:3321@10.134.27.2>;tag=1417F2E5-2588
"--CVP_13_00xx..ssdadsalds_349" <sip:05335816023@10.134.27.2>;tag=1417F2E5-2588
';
$subst = "\1";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
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