Hi Skaterdad,
When I wrote this post, I was thinking you are using a WinGate server. But from what I have reread, you have NAT connection to the internet via the cable modem, and you want to set it so when the cable modem is down, to fire up a different gateway. What software will you run to invoke this?
Will it be
a) LAN Computers --> WinGate --> Cable or Dialup
b) LAN Computers --> Some other SW --> WinGate server if cable down
1. The modem could be on another computer, but I have configured it in this example as if it is on the WinGate computer.
So first thing is to setup the dialer to work with your modem.
Then go to the WWW Proxy Service and configure the Gateway option (Some other services have the gateway option too)