Answered & edited !
I have a single Wordpress installation on example.com.
I use Polylang plugin to add multilingual system to this website. I have 16 languages, and it's configured to use example.com/fr for French, example.com/de for German, etc ...
I want to use domain name for Korean language and Japan. Instead of example.com/jp, I want to get the website on example.jp.
I'm trying to find a way to do this with .htaccess without moving the others languages on sub domains or domains.
Here is what I have, but if I go to example.jp/page/ I'm redirected to example.com/ja/page/, do you know a way to hide this redirection ?
# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} ^(www\.)?example\.jp$
RewriteRule (.*) http://example.com/ja/$1 [R=302,L]
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
# END WordPress
Another information if you need, the domain are using CNAME, and I'm on a WP Engine hosting. Concerning permalinks, I'll be able to pass them into a filter to clear the current subdirectory links system.
Thanks for your time !
EDIT : As explained in the answer, the CNAME and server file system gives me everything I need. I don't need to use .htaccess to achieve what I'm looking for.