Disabling cache on remote_addr

Hi,
I’m using this stanza to configure caching on jpeg|css|gif files:

location ~ .(gif|jpg|png|css)$ {
proxy_pass http://1_2_4_backend;
proxy_cache STANZA00;
proxy_cache_valid 200 10m;
proxy_cache_use_stale error timeout invalid_header updating http_500
http_502 http_503 http_504;
}

But I have to disable caching depending on remote_addr.

How could I accomplish this?

Thanks in advance,
d.