Htaccess, subdomains & subfolders ?

Hi guys,

Looking to implement some subfolders, where each have a Codeigniter FW.
All my subdomains goes to the "principal folder" and a .htaccess redirect there to the good folder, like that : 

Code:

Options +FollowSymLinks
RewriteEngine On
RewriteCond %{HTTP_HOST} ^(.*)\.apps\.xxx\.io
RewriteRule ^(.*)$ http://app.xxx.io/_deployed/%1/index.php/$1 [P,L]

Example : 
- app1.apps.xxx.io
- app2.apps.xxx.io
- etc...

In each "subfolder", I have another .htaccess for my codeigniter FW, but I think this implementation is not good :

Code:

RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php/$1 [L]

Anyone can save me ? 

Thanks for your help.