Distortation of engineering drawing in Ms Excel
I am assuming that the reason you are using Excel is because of the gridlines. An "engineering drawing" done in Excel would break when rotated especially the angular lines. The reason is Excel does not have the necessary engine to display (render) such drawings. By Excel alone, there is no way out of this problem.
However, there is a workaround. After making the drawing, before rotating it, do a Print Preview. Open an image manipulation program, even a simple one such as PaintShop Pro. Capture the image on the Print Preview. Open another Excel sheet, copy and paste the image from the image manipulation program to the Excel sheet.
Hope this be of initial help/idea. Pls post back how things turned up or should you need additional information. Good luck and kind regards. Thank you for using FixYa.