HTACCESS rewrite if multiple cookies found - wordpress

Question

I'm scratching my head trying to do make a htaccess redirect in case of a cookie is found.
I have several directories /fr-be/, /nl-be/, /en/, ...
When a user visits a page in those directories a cookie named "lang" is dropped with the corresponding directory name so 'fr-be', 'nl-be', 'en', ... as value.
If the user manually type the url : 'https://testme.com' and if the cookie is found it should be redirected to the corresponding dir.
If there is no cookie found, it should be redirected to a default dir '/en/'
If there is something else than '/en/' like https://testme.com/en/test-page/ it should not be redirect.
It is a wordpress that's why there is a ". /index.php [L]" at the end.
I can't use php redirect because the website is on a static (strattic) server
Thanks for you help !
Here is my code :
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{HTTP_COOKIE} lang=fr-be
RewriteRule ^/$ /fr-be/ [L,R=302]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{HTTP_COOKIE} lang=nl-be
RewriteRule ^/$ /nl-be/ [L,R=302]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{HTTP_COOKIE} lang=en
RewriteRule ^/$ /en/ [L,R=302]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^/$ /en/ [L,R=302]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>