$re = '/(\d+)\.\s"([a-zA-Z ]+)"\s[a-zA-Z \.]+\s([a-zA-Z, \.]+)\s([\d:]+)/m';
$str = '1. "Anbae Anbae" Vairamuthu Hariharan, K. S. Chitra 5:10
2. "I Love You" Vairamuthu Nandini Srikar, KK, Ajith Kumar 4:55
3. "Nathi Enge Valaiyum" Vairamuthu Ghanshyam Vaswani 4:37
4. "Nothing Nothing" Vairamuthu Harini 4:44
5. "Poovukellam Siragu" Vairamuthu Srinivas, KK, Harini 5:27
6. "Vannakili SolKonda" Vairamuthu Gopal Rao, Harini, Chorus 4:38';
$subst = "\1 \2 - \3 \4";
$result = preg_replace($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