How to go about getting pregnant?

There is a good guy friend that I have known for 6 years. He has great attributes and qualities that I love about him. Though, I don't want him to be the father but a donor. What will be the best method of doing this. I have asked before but he has said no. But, I want to readdress it again to see if he can reconsider. Honestly, I don't want to be sneaky and seduce him into have unprotected . (Of course, I will pay to get his health check out first by a doctor.) He just has the qualities that I am looking for. Any advice will be helpful...hopefully.