Multidimensional SortedList (C#)

[AxessTerminated]

I am trying to create a 2-Dimensional SortedList in C#. I need to be able to look up a value using two keys, much like x,y coordinates.

See the table below. I need to be able to input two keys (A,C) and have the value '3' returned. The keys are an enumeration I have and the values will be integers. The standard C# SortedList only supports one key to one value. How can I best do this in C#?

Using this:

public enum letters
{
    A=1,B=2,C=3
}

  A B C
A 1 2 3
B 2 3 1
C 3 1 2