ruby - Calling scp from net:ssh

Question

Here's the setup:

I have server A, which is running my ruby scripts and servers B & C. I need to be able to transfer files from B to C.

I've experimented with using Net:SCP, but I haven't found a way to set up a transfer between the two remote servers. The best I've been able to do was go from B to A and then from A to C.

Based on some example code I've seen elsewhere, I'm trying to ssh onto B and call scp from that server:

Net::SSH.start(host, user, :password => pword) do |ssh| 
  ssh.exec! "scp /filename user@serverC:/filename" do |channel, stream, data|
    channel.send_data "#{pword}\n"
  end
end

This is not working for me. Is this even possible?