adding exception in htaccess

Folks,

I am not able to find the right Board for this topic, so positing it here... Should it go in Server Board?

My current .htaccess code is as follows:

<IfModule mod_rewrite.c>
  Options +FollowSymLinks
  RewriteEngine On

  # Get rid of index.php
  RewriteCond %{REQUEST_URI} /index\.php
  RewriteRule (.*) index.php?rewrite=2 [L,QSA]

  # Rewrite all directory-looking urls
  RewriteCond %{REQUEST_URI} /$
  RewriteRule (.*) index.php?rewrite=1 [L,QSA]

  # Try to route missing files
  RewriteCond %{REQUEST_FILENAME} !-f
  RewriteCond %{REQUEST_FILENAME} public\/ [OR]
  RewriteCond %{REQUEST_FILENAME} \.(jpg|gif|png|ico|flv|htm|html|php|css|js)$
  RewriteRule . - [L]

  # If the file doesn't exist, rewrite to index
  RewriteCond %{REQUEST_FILENAME} !-f
  RewriteCond %{REQUEST_FILENAME} !-d
  RewriteRule ^(.*)$ index.php?rewrite=1 [L,QSA]

</IfModule>
sends requests /index.php/path/to/module/ to "index.php"
AcceptPathInfo On
@todo This may not be effective in some cases
FileETag Size

Now, i want to integrate a script with this htaccess... Here is what the script says..."add exception to execute all the index.php files inside the /cometchat directory and its sub-directories on your server."

SO, how can i add the exception to execute the Index.php from this directory, at the same time do not hamper the existing .htaccess code...

Anyone please?