Controling my shared DUN over wifi network

After an exhausting search I found no solution.

Ok. let me explain.

X51v using DHCP 192.168.0.xxx range, connects to wireless linksys

router (router functions just as a hub/accesspoint without an internet connection)
Also have two wireless laptops connected the same setup one running WinXP and the other running Win Vista.

Router connects to a WinXP Desktop PC (host) via wired ethernet
Router IP = 192.168.0.2 (had to change default router IP to use the
host's shared dialup connection)

WinXP Desktop PC static IP = 192.168.0.1 (acts as host/gateway to internet)

56k dialup to internet
Internet connection sharing
1. Allow other networks to connect through this computer's internet
connection. (checked)
2. Allow other users to controll or disable the shared internet connection. (checked)

Can browse internet and network from all computers and devices.

Problem
Can't see or control (at will) the dialup connection remotely via X51v.
Also,
Can't see or control (at will) the dialup connection remotely via laptop Win Vista.

However,
I can see and control it with my laptop running XP.

Any idea's / solutions?

I can check the Internet connection sharing option
Establish a dialup connection whenever a computer on my network
attempts to access the Internet.
and that works on all devices, but then you have to deal with the timeout setting etc. Plus some programs I have check for updates automatically, antivirus, etc.

I would rather be able to manually enable/disable internet connection remotely.

Is there anyway to create a shortcut of sometype for remote dialup on my
X51v like the one I have on my laptop?