The first thing that comes to mind is an SSH tunnel. However, FTP is not the most tunnel-friendly protocol (it is somewhat possible, see wikipedia for details).
To forward a port from your laptop to your work computer (126.96.36.199) via your house computer (188.8.131.52), you can do something like:
ssh -L10099:184.108.40.206:99 220.127.116.11
Now accessing local port 10099 will connect you to your work computer port 99 (I do not remember if there are some settings to change in
If tunneling does not work, another possible option in Linux is to ssh to your home computer and download the files there, then you can mount the directory locally with
sshfs. Just a bit better than double FTP (work->home->laptop).
Finally, you can set up a VPN between your laptop and house and have ad-hoc IP routing to your work computer.