Help!! I'm new from VNC!

Hello, I’m feel a bit stupid…but I’ve tried most of everything and I can’t use Vine viewer/server from outside.
Here is the story
At home I have an iMac with wireless connection and the Vine server 3.0 installed, the router is Airport Express.
In the office I’m using a MacBook Pro and the Vine viewer 3.0 is installed.
Both computers running the OSX 10.5.1

I’ve followed the instructions and I’ve setup the viewer and the server in ssh. On the Airport Express I’ve mapped the port 590x and the port 22

in Airport Express/Port Mapping there are “Public Port” “Ip Address” and “Private Port”. I’ve set the “Public Port” and the “Private Port” with same value, I hope it is correct?

On the SSH login of Vine viewer the SSH Host must to be the same IP of my router or the IP of my iMac?

Every time I try to connect a window come up with this text “Connection failedUnable to Connect To VNC Server through SSH”

I’m sure it will be some stupid things that I’ve forgot but sorry it’s first time that I’m using this program.

Thanks a lot in advance