Ssh port forwarding with Remote Desktop timing out

Ssh port forwarding with Remote Desktop timing out

My work computer, a Windows 7 Enterprise PC called WORKPC, is running
Remote Desktop. I have configured Windows Firewall on WORKPC to allow
access to the Remote Dekstop service from only two IP addresses: IP1 and
IP2.
IP1 comes from a commercial VPN service that allocates me a static IP
address. When I go home and run the VPN client I can connect to WORKPC
using the Remote Dekstop client with no problem.
IP2 is the address of a Linux server GATEWAY at work I can ssh into from
home. In order to use IP2 to remote desktop to WORKPC I use ssh and port
forwarding on IP2:
ssh -vvv -L 1234:WORKPC.example.org:3389 GATEWAY.example.org
When I attempt to remote desktop from home using this port forwarding
technique, I get the following error on my ssh connection:
debug1: Connection to port 1234 forwarding to WORKPC.example.org port 3389
requested.
debug2: fd 9 setting TCP_NODELAY
debug3: fd 9 is O_NONBLOCK
debug3: fd 9 is O_NONBLOCK
debug1: channel 3: new [direct-tcpip]
channel 3: open failed: connect failed: Connection timed out
To verify that port 3389 was open on GATEWAY I did a telnet 3389 and got a
connection, so I am certain that port 3389 on WORKPC is open to GATEWAY.
I would prefer to use the ssh proxying method over paying the commercial
VPN service to rent a static IP address. Can anyone suggest something I
can try to get this to work?