Redirect to subfolder

For .htaccess to redirect to subfolder, add and .htaccess file to the root with the following content:

RewriteEngine on
RewriteBase /

RewriteCond %{REQUEST_URI} !^/path/to/folder/

# Rewrite all those to insert /path_to_folder_from_root
RewriteRule ^(.*)$ /path/to/folder/$1 [L]