Any one please help me.I am new to .htaccess

I want to check the following condition

RewriteCond : IF !index.html AND !app/facebookapp/{[a-zA-Z0-9-/]}.html
RewriteRule : .....

My code is

RewriteCond %{REQUEST_URI} !index\.html 
RewriteCond %{REQUEST_URI} app/facebookapp/^([a-zA-Z0-9-/]+).html$ 
RewriteRule ......

its not working

And one more question

if the request url is header.html

RewriteCond %{REQUEST_URI} header.html$ 
RewriteRule ^([a-zA-Z0-9-/]+).html$ position.php?position=$1 [L]

$l will return header.

if the request url is app/facebookapp/header.html we write the same above condition $l will return app/facebookapp/header.my question is how to get only the filename ??

thanks