Picking up from Andy's advice. An Excel spreadsheet really is an extremely powerful program. I would not underestimate it.
What I would suggest is merging the excel spreadsheet into access. There are several sample databases that you could use. For a nomimal fee, you can download one set up for calibration.
Your basic information will be there for the form: test points, tolerances, model/serial number, etc. Then, you can you a select box and go to reports and print out the certificate.
There are sooo many different forms, it would do no good to put one here. The form I follow is this:
1. My company name.
2. customer name
3. U.U.T. (Unit Under Test) information.
4.Standard to be used, tolerance, due date
5. U.U.T. model, serial number, and tolerance
6. Test points/ As found/ As left data
7. Pass/fail
8. Specification used
9. Comments
10 Name/signature.
Too, go to some calibration labs website and many times they have sample calibration certificates. Choose one similar to your requirements and the instruments you are calibrating.