analize financial frontiers with rolling windows

I need to analize with Rolling Windows 20 years of monthly financial data, I should bring the first 5 years and calculate the tracking error variance frontier and a lot of other parameters, then, month after month, I have to move the window and redo all the calculations produced. As I have 240 observations I think it's better use a for-loop, but I'm not very familiar with for-loop and also with matlab. Can someone help me? Thank you!