How to SSH into router and port forward to lan?

I've got SSH all set up on the router. Now I want to Port Forward from SSH on the router to a computer on the internal lan. I can't seem to access anything on the Lan. Any ideas?

Don't understand. Steps/picture/more info would help.

More info

I'm talking about ssh port forwarding. I'm trying to do somethink like this from Plink(command line version of putty):

plink -L 2000:[IP in Lan]:3389 root@[Router IP]

The point is to connect to remote desktop through an SSH tunnel and possibly other services if I can get this to work.

Got me. Sorry

This works for me:
plink.exe -l root -L 127.0.0.2:3390:[IP in LAN]:3389 [Router IP]

Thanks

Thanks beanbaxter works great. I thought I tried that, guess not. Sometimes it just helps when someone else confirms something can be done.