Ubuntu 14.04 Nginx Rewrite rule issue

Question

Problem with nginx mod rewrite. Really appreciate help. I spent hours on that issue

Problem with rewriting url.

I want rewrite from bangots.eu/?subtopic=highscores bangots.eu/?subtopic=houses

to get this

bangots.eu/highscores bangots.eu/houses

I have this code

rewrite ^/([^/]*).html$ /?subtopic=$1 last;

and 2 things are wrong with that. 1. I dont want .html extension 2. This rewriterule take me from bangots.eu/highscores.html to bangots.eu/?subtopic=highscores. I want reverse it. Thx for any help!

That is piece of my /etc/nginx/sites-available/default

server {
        listen 80 default_server;
        listen [::]:80 default_server ipv6only=on;
        root /usr/share/nginx/html;
        index index.html index.htm index.php;
        # Make site accessible from http://localhost/
        server_name bangots.eu;
        location / {
                # First attempt to serve request as file, then
                # as directory, then fall back to displaying a 404.
                try_files $uri $uri/  index.php$is_args$args =404;
                # Uncomment to enable naxsi on this location
                # include /etc/nginx/naxsi.rules
                rewrite ^/([^/]*).html$ /?subtopic=$1 last;
        }