Lighttpd

I am pretty new to lighttpd and am using it to reverse proxy a local running crun process under a local ip: 10.200.1.2. I have gotten the proxy working, so it proxies the call correctly from localhost/customer into my 10.200.1.2 process on port 80. But now (in my view), I need to also fix all paths that are returned (they are returned in html as /static/js/main.js but should be returned as /customer/static/js/main.js, how can I do this?

My config:

$HTTP["url"] =~ "^/customer" {
        proxy.server  =  ( "" => ( "" => ("host" => "10.200.1.2", "port" => 80 )))
        proxy.header = (
                "map-urlpath" => (
                        "/customer" => "/" 
                ),
        ),
}