Maybe another way to do it would be to set up a second backend instance of nginx on another port which serves all the php dynamic.

1. http client makes request 2. if static is required and available the front nginx serves it 3. if no static is found the request gets proxied to the second nginx server with php fastcgi

Your 2nd Nginx would have your normal rewrites and the fastcgi php set up and your first file could look like this. I haven't had time to test this.

upstream 2ndNginx { server 127.0.0.1:82; }

server { listen 80; server_name supercachestatic.com; location / {

root /var/www/mydomain.com/htdocs; index index.html;

if ($query_string !~ ".*s=.*") { rewrite ^(.*) /wp-content/cache/supercache/$http_host/$1index.html; }

if ($http_cookie !~ "^.*comment_author_.*$" ) { rewrite ^(.*) /wp-content/cache/supercache/$http_host/$1index.html; }

if ($http_cookie !~ "^.*wordpressuser.*$" ) { rewrite ^(.*) /wp-content/cache/supercache/$http_host/$1index.html; }

if ($http_cookie !~ "^.*wp-postpass_.*$" ) { rewrite ^(.*) /wp-content/cache/supercache/$http_host/$1index.html break; }

error_page 404 = @2ndNginx;

location @2ndNginx { proxy_pass http://2ndNginx;