Question : Problem: setting up no-ip account so that I can vnc onto my net work and view a pc on the net work

I have set up a no-ip account and can access what is effectivley my modem config info which I could change if some one wanted to. What I am trying to do is I have a adsl modem with 5 pc sitting on a swich which is effectivly my network, what I need to be able to do is to go through no-ip site and access one of the pcs that is on my network so that I can connect via vpn and then change what I need to on my pc that I want to connect to.
So I have created a no-ip dns that is auto updated after the modem is reset and this all works.
Question now is how to I access my pc that sits under the default gate way, but I still do not understand what I have to configure the VPM and then the realvnc to access the PC on the net work. easy if you have done it once
Thanks for the help in advance

Answer : Problem: setting up no-ip account so that I can vnc onto my net work and view a pc on the net work

The following Speedtouch Document may help with your configurations.
Configuring your DDNS service with no-ip is outlined in section 4.5.12
Port forwarding is outlined within the "Assign a game or application to a specific network device" section (4.5.2). Though it allows you to define a new game or Application, see if there is a PPTP (or Point to Point Tunneling) existing application in the list. I would assume this will enable GR. I believe if the firewall section is set to "Standard" it will not affect your VPN, but if stuck try disabled mode.
http://www.ccsleeds.co.uk/KB/Routers/ST536v6.pdf