List<string> tracks = new List<string>();
tracks.Add("track\\3. - Bla bla");
tracks.Add("track\\1. - Bla bla");
tracks.Add("track\\10. - Bla bla");
tracks.Add("track\\2. - Bla bla");
tracks.Add("track\\25. - Bla bla");
List<string> newtracks = tracks.OrderBy(track => int.Parse(Regex.Match(track, @"(?<=track\\).*?(\d+)").Value)).ToList();
foreach (var t in newtracks)
{
project.SendInfoToLog(t);
}