Hi,
just wanted to post this link here:
https://github.com/shred/acme4j/blob/master/acme4j-example/src/main/java/org/shredzone/acme4j/ClientTest.java
This is an open source JAVA library for ACME generation.

It should be possible to use it and completely automate the process of certificate generation in an Notes-Application.

It wont have time for it till summer. So if anyone is interested in developing it he is welcome.