$re = '/^([^-]+) - ([^-]+) - ([0-9]+\.) (.*)$/m';
$str = 'Nirvana - From The Muddy Banks Of The Whiskah - 01. Intro.mp3
Nirvana - From The Muddy Banks Of The Whiskah - 02. School.mp3
Nirvana - From The Muddy Banks Of The Whiskah - 03. Drain You.mp3
Nirvana - From The Muddy Banks Of The Whiskah - 04. Aneurysm.mp3
Nirvana - From The Muddy Banks Of The Whiskah - 05. Smells Like Teen Spirit.mp3
Nirvana - From The Muddy Banks Of The Whiskah - 06. Been A Son.mp3
Nirvana - From The Muddy Banks Of The Whiskah - 07. Lithium.mp3
Nirvana - From The Muddy Banks Of The Whiskah - 08. Sliver.mp3
Nirvana - From The Muddy Banks Of The Whiskah - 09. Spank Thru.mp3
Nirvana - From The Muddy Banks Of The Whiskah - 10. Scentless Apprentice.mp3
Nirvana - From The Muddy Banks Of The Whiskah - 11. Heart-Shaped Box.mp3
Nirvana - From The Muddy Banks Of The Whiskah - 12. Milk It.mp3
Nirvana - From The Muddy Banks Of The Whiskah - 13. Negative Creep.mp3
Nirvana - From The Muddy Banks Of The Whiskah - 14. Polly.mp3
Nirvana - From The Muddy Banks Of The Whiskah - 15. Breed.mp3
Nirvana - From The Muddy Banks Of The Whiskah - 16. Tourette\'s.mp3
Nirvana - From The Muddy Banks Of The Whiskah - 17. Blew.mp3';
$subst = "$3 Album: $2 From $1 - $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