Er, I think we’re talking about certificates of the “I hereby certify that HenryAZ has won today’s ‘wrong end of the stick’ award” variety rather than the encryption variety (unless the thread starter is a
real wizard in PowerPoint)!
For the sort of certificates that
@0989382 was talking about, if you can set the certificate layout up in PowerPoint, you can probably achieve the same in Word and then use the mail merge facility to run off a batch of certificates with names taken from a spreadsheet. (I don’t think PowerPoint has mail merge).
For the SSL sort, try
https://github.com/jsha/minica (not what 0989382 was after, I suspect)