Using Upnp for Port Forwarding - Wan Interface

Hey guys,

I would like to know if it is possible to use Upnp to open/forward a port to another router connected to the Wan interface?

I am interested because my setup is a router behind a router. I would like to open port 3389 for rdp connections. I can set up manual port forwarding rules in the second router, but I cannot in the first. Is there a command I can issue from my second router to se up a port forwarding rule using Upnp.

Thanks,