Configuring terminal server

I wonder if anyone can help, I am totally new to this so
bare with me.

I have set up terminal server on a windows 2000 server
and I have got it working on the Lan. I would like to get
it working over the internet. Now the box the terminal
server resides on has an IP address of 192.168.56.8 I
have a firewall in the network that has another internal
private IP address and a public IP addresss and finally I
have a broadband router with another public IP address.

I am not sure how to configure this to get it working in
administration mode.


Thanks In Advance


Martin