rewritecond exclude url in .htaccess - wordpress

Question

I have these working rewrite rules :
# Allow access to assets folder from plugins folders
RewriteRule ^app/plugins/(.+)/assets - [L]
# forbid access to files and folders under app
RewriteRule ^app/.*$ - [L,F]
# rewrite to index.php
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php?action=$1 [L,QSA]
Now I would like to exclude from these rules everything located under http://www.mywebsite.com/wordpress/...
Therefore I've added a new rewrite condition :
...
# rewrite to index.php
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_URI} !^\/wordpress\/ [NC]
RewriteRule ^(.*)$ index.php?action=$1 [L,QSA]
But it dosen't work. When I try to access something like this :
http://www.mywebsite.com/wordpress/contact-us/
it redirects me to index.php...
Any help would be really appreciated.

Answer 1

Ok I finally found what was going wrong with all of this :
In fact I did not notice that a .htaccess file was present in my /wordpress directory.
So on the .htaccess of my root directory I've added this rule on top of all the others :
RewriteRule ^wordpress - [L]
Then in the .htaccess of the wordpress directory I've these rules :
RewriteBase /wordpress/
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /wordpress/index.php [L]
I don't know if everything is optimized but it works !