streaming mp4/flv from external http server

Hi

I have problem with configure mp4/flv streaming on nginx. I will explain what I want to do.
I have storage movie server (flv/mp4/mkv/avi) and it works by lighttpd. I'd like to set up nginx server (external server) to streaming currently downloaded file (realtime) from storage server to nginx stream directory (automatic application) and play it from external player for example xbmc (in realtime).
I've tested it, and it was playing on xbmc, but if download file from storage server to nginx streaming server was slower like got data to xbmc player then xbmc stopped play.

[storage server on lighttpd] ----> [nginx streaming server] <----> player (xbmc)

Is the way to configure nginx (or external applications) it to works correctly?

I can't install nginx on storage server (dedicated system).

I've tried searching any solutions on net, but without results.
Thanks