How to Write Regular Expression

Try:

using System;
using System.Text.RegularExpressions;

class Test
{
   static void Main()
   {
      string str ="((G011, G012))";
      MatchCollection mc = Regex.Matches(str, @"\w+");
      foreach(Match m in mc) Console.WriteLine(m.Value);
      Console.ReadKey(); 
   }
}

The output is:

G011
G012