Proxying a remote munin server

Hi NGINX comunity!

Has anyone ever tried (or succeeded!) on proxying a remote munin server?

What I'm trying to do is to create a location on my nginx server vhost (let's say "/graphs").
Then, under /graphs, I want to let nginx to proxy the graphs structure from a remote munin (CGI driven) server (let's say http://my-munin-server/munin) ...
Obviously, this still sound no tricky (even me, I have succedded on doing this) unless the las thing I really want:
I do not want the whole /munin graphs structure to be proxied under /graphs , but I only want a portion (for privacy reasons) of the munin graphs structure to appear under /graphs (let's say I want to proxy just http://my-munin-server/munin/my-domain.com).

I have even succeded on doing this, but the results are partial, and from this endpoint I habe been several days googling with no success:
The problem is that I got the site proxied with no css, no static contents, no images ... so it all is useless
By reading the code I see plenty of ../ ../.. ../../../ on the original munin server code, so I guess I have a relative path problem, but I have not succeeded on solving it using rewriting / proxy_pass stuff.
munin server itself is nginx driven, and uses the widely / googlely available "munin over nginx setup"

Nobody at the munin comunity seems to have ever tried or succeeded on this, so they expect someone to be the first and let it be documented... but it is beyond my knowledge

So... I thought we may got a chance hitting directly on the hornet's nest (NGINX comuninty!)

Anyhow, thank you very much for your curiosity!
Best regards!