Reverse Proxy: Dissimilar URL's

So I know how to reverse proxy http://outside/foo to http://inside/foo. How do I reverse proxy http://outside/foo to http://inside/bar? Here is my attempt that does not work:

bbCode doesn't seem to work here, and Google doesn't help me to figure out how to insert a code block into Phorum.

location ^~ /Foo {
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Host $http_host;
proxy_redirectoff;

proxy_pass http://inside-IP/Bar/;
}