base36.cs

using System;
using System.Text;

namespace Blah {
	public class Program
	{
		public static void Main (string[] args)
		{
			const string base36 = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
			ulong value = ulong.MaxValue;
			var id = string.Empty;

			value = (ulong) args[0].GetHashCode ();

			do {
				id = base36[(int) (value % 36)] + id;
				value /= 36;
			} while (value != 0);

			if (id.Length < 13)
				id = new string ('0', 13 - id.Length) + id;

			Console.WriteLine ("id = {0}", id);
		}
	}
}