Using Excel 2007, proof stress calculation can be automated by creating a line with a y-intercept at 0.2% and a slope matching the initial slope of the material's stress-strain curve. The point where this line intersects the curve indicates the proof stress. This method allows for a systematic approach to determining proof stress without manual calculations. Users expressed gratitude for the guidance and indicated plans to try the method soon. Overall, the discussion highlights an effective way to utilize Excel for material stress analysis.