Applying coordinate data to matrices without plotting them

I have a cell array, each cell of which contains a matrix of equal size. I then have a GUI which will plot the first of the matrices. What I need to do is set four markers on the plot to form a square or rectangle which is essentially and area of interest. Once I have determined this area I will get the sum of every value contained inside. My question is, is it possible, once I have selected these points, to apply this 'area of interest' to each of the rest of the matrices, carry out the same calculation and tabulate the data. I planned on using the data cursor tool to select the four corners of my area of interest and I have researched how to tabulate results calculated by matlab. My main query is, can it be done? Can the same region of a matrix be specified across an array of matrices without plotting each one individually?

[Adam]

Yes, you just use a logical data mask which determines the points inside and outside of your region of interest. This mask can then be applied to any matrix of the same size.

[Aaron Smith]

Using a mask does not overwrite the actual values inside the ROI does it? Because of the binary nature of masks?