Thomson TG585 v7 - port forwarding tied to a single external IP address

[#1]

On my old BT Voyager 2100, I configured ports 22 (Secure Shell Server) and 873 (rsync) to port forward to a server on my network and locked them down to a specific external IP address.  This could be easily done through the GUI on the Voyager through the Port Forwarding configuration page.  I want to do this on my new Thomson TG585 but as far as I can tell cannot use the GUI to constrain access to these ports from a specific external IP address.  I have downloaded the CLI manual but am not sure which commands I need to issue.
Can anyone tell me which CLI commands I should use to achieve this aim?
Many thanks,
pgm

[#2]

Ok a bit more difficult in the thompson ones.
Just tried on my 716 (basically the same s/w)
You need to do the following:-
Open the Firewall settings
Create a NEW firewall set
On the next page click edit
then create a new rule from the ip you want on the wan to the port/ip you want on the lan
then set the new firewall set as active
Not very clear is it?
Hope that helps.
I don't use the firewall on the router but use a separate Linux based firewall, but then I am paranoid  But I have never been hacked even with several ports open (web/mail/ftp etc)
K