Regex reg = new Regex(@\"^[0-9]*\\.wav\"); Stack wavefiles= new Stack(Directory.GetFiles(\"c:\\\\WaveFiles\", \"*.wav\").Where(path =&
You can also do it without Regex
var files = Directory.GetFiles("c:\\WaveFiles", "*.wav") .Where(f => Path.GetFileNameWithoutExtension(f).All(char.IsDigit));