Card Sort Analysis using Excel (Agreement and Disagreement Matrices)

I'm trying to find way to tabulate the results of an open card sorting exercise. We have about 50 cards total and need to pair that down so I'm hoping to crunch the numbers in excel to see where there was high/low agreement between cards.

I've found a couple of spreadsheets that do other forms of analysis, but none that do the matrix. Does anyone know where I could find one?