It could be a typical port forwarding case, but it is quite confusing for me. I have a machine A which has to connect to C. I can't edit any settings in A, except the destination it has to connect to. It can't connect to C directly due to proxy issue. I want machine B to be setup in such a way that it can listen for an incoming connection from A, and forward to a connection to C. C doesn't like a dedicated connection, so B should establish a connection to C only after A requested one. I can't edit the settings in 'C' either. Any help on how to do this would be great.
Is this what you want?