Mine

using System;

public class Test {

	public static void Main(string [] args)
	{
		int i = 1;
		string escaped = "a%D0%05b";
		char a = Uri.HexUnescape (escaped, ref i);
		Console.WriteLine ("i is now {0}", i);
		Console.WriteLine ("char is {0} {1}", a, (int) a);
	}
}