Hello Sebastian
I have several quality documents made by myself in Microsoft Excel. As you, I have Initial Process Study, Calibration Report, Dimensional Report and so one. All had formulas and macros, because I like simplify jobs with efficiency.
Of course, when you made a new document with formulas, you must test very well each result, preferentially use a similar document/software already approved to confirm your results (don’t forget to put the same data in both documents)

or made the calculations manually first. When the final result is equal in both, you can consider your job almost done... because I advise you to protect and approve the document to show auditor how as made and approved.
To made my Initial Process Study I use this site as standard...
http://www.statpoint.com/capability_analysis1.htm
I hope my tips help you a little