Please provide some information how to jump to a place not at the top of the page / example chm file where this takes place. Been searching the Internet but didn't find a suitable example.
(Example / description in German is OK for me too).

One example would be the inbuilt help of POV-Ray for Windows.

There's really no black magic to it: Just have the index.hhk point to the corresponding anchor on the HTML page, like so:

<LI><OBJECT type="text/sitemap"><param name="Local" value="mypage.html#myanchor"><param name="Name" value="Foo"></OBJECT>

But I've thrown together a corresponding patch already; expect a pull request within the next few hours.

Thanks, I've merged the pull request

This bug was previously marked ASSIGNED, which means it should be fixed in
doxygen version 1.8.12. Please verify if this is indeed the case. Reopen the
bug if you think it is not fixed and please include any additional information 
that you think can be relevant (preferably in the form of a self-contained example).

The fix seems to be working properly in 1.8.12, thanks.