At ifilm.com I found a video called “Tips on how to solve any Sudoku puzzle”, Posted by kimberlyredcup22.
The video describe how to solve any Sudoku puzzle with the use of Excel or any other spreadsheet program. There is only one mistake they made at the end (around 1m34 they remove the a nine in one of the cells in the upper right square (3×3), and also the nine in the corresponding row and column, but they forget to remove the nine in the other cells in the upper right square.
The video visualize at least how this Sudoku solving technique works. Happy Puzzling!