Convert a few htaccess rules to nginx

Hi

I am looking for a way to convert htaccess rules to nginx rules so my IPBContent will work ....:

RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !.*\.(jpeg|jpg|gif|png|ico)$
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]

Can anyone please help?

Thanks