using System;
using System.Text.RegularExpressions;
public class Test
{
public static void Main()
{
String input = @"
...
string 1,string 2,string 3
...
";
Regex rgx = new Regex(@"(?:|\G),?([^<>,]+)");
foreach (Match m in rgx.Matches(input))
Console.WriteLine(m.Groups[1].Value);
}
}