Kirby at root, second domain not-kirby at subfolder - hide subfolder in url

Hey there…
i am using kirby at root with multisite setup, like described in here:

On the same server i use several domains like:
kirbydomain1.de → dom1/content/
kirbydomain2.de → dom2/content/
kirbydomain3.de → dom3/content/

Many other Domains are redirected to kirbydomain1.de… but now, i need a simple onepager on a complete new domain… since kirby-license does not allow me to have another multisite-domain inside kirby (unless i pay for another license). i want to redirect the newdomain.de to a subfolder with a simple html file which is not served via kirby.

i searched web for solution and found this: regex - htaccess redirect + hide subfolder in url - Stack Overflow

Now, in my kirby .htaccess i redirect this single domain like this:

RewriteCond %{HTTP_HOST} ^(www\.)?newdomain\.de$   
RewriteRule !^subfolder/ /subfolder%{REQUEST_URI} [R=302,L]

Now, when i open newdomain.de i will be redirected to newdomain.de/subfolder and the index.html inside subfolder is loaded…

This first stage is wanted… but how to hide the subfolder from beeing shown in the URL?

The stackoverflow-Link says, the subfolder should be hidden… is this not happening because of kirby and/or kirby-specific rules in .htaccess?

Any idea, how to hide the subfolder from URL when using newdomain.de to access newdomain.de/subfolder/index.html?

p.s. oh… and the subfolder should not be accessible via kirbydomain1.de (which it is actually, too)

Then just set up a new folder outside of kirby folders, point the new domain to that folder and you are done. No need to hide a subfolder because it does not exist.

thx… this would be for sure an easy setup… but currently i can not go higher level… kirby lays at root on a docker container.

since i don’t manage the docker-part. i seem to have to wait for the admin who is responsible for that… but everything is time-critical…

Admin implemented a new docker-container with a webserver…