How to access Transmission runing behind a NAT from external PC

I have two PCs at two different places. Ons is behind a firewall I cannot (place X) control and the other is at my home.

Transmission has a way of adding/ removing torrents using a web interface. http://ift.tt/1COFFiZ

Now I can use the above url when I am using the PC X but when I am at home I cannot control Transmission.

I have a third Amazon EC2 instance which can be used to set up tunneling or back SSH sessions.

I understand I can easily do this using team viewer. But that way I will not learn anything.

I want to do some data forwarding through ports and get the web interface of transmission from my home PC which has a public IP.

Amazon server has a public IP as well. All PCs have admin privileges and they all run Linux.

I've previously controlled PC X using a back SSH session to my Amazon server and then forward SSHing from my home to Amazon Server thereby forwarding my SSH packets to PC X. can something similar be done for this as well?