We have CLIENT, GATEWAY, REMOTE. Need to copy CLIENT->REMOTE.
##OPTION 1## (in one line)
#!bash
scp -rp -o "ProxyCommand ssh GATEWAY_USER@GATEWAY -p GATEWAY_PORT -W REMOTE:REMOTE_PORT" PATH_FROM REMOTE_USER@REMOTE:PATH_TO
##OPTION 2## (two lines)
#!bash
ssh -L CLIENT_ANY_PORT:REMOTE:REMOTE_PORT GATEWAY_USER@GATEWAY -p GATEWAY_PORT&
scp -rp -P CLIENT_ANY_PORT PATH_FROM REMOTE_USER@localhost:PATH_TO