Massive Statistical Number Crunching

I have been charged with the task of running some basic statistics calculations on a very large set of data in Excel 2007. Basically, I need to find the min, max, and average of the rows and columns, which isn't the hard part of the problem.

The hard part is that the data is spread across 1300 xls files, and each one contains about 50,000-500,000 or more cells of data. I need a fast way to read all this in, do the math, and then export the results back into an Excel sheet. I'm afraid VBA would die trying to do this, or would take eternity. Or at least, if VBA was the best way, have someway of displaying the number of files it has finished so the user isn't left in the dark with no ETA.

I've been wondering if using the Excel object in C# would be a better way to read the data in first, and then write a nice, neat Excel file afterwards, but I'm not familiar with Excel object, nor do I have Visual C# here with me at the moment.

Any ideas?