Ahhhh. That's an interesting behavior oddity in the START command.
The "Start" command's first parameter is actually a window title. So you're actually telling start to create a new window with the title "c:\program files...", and then you're launching the .pp2 file, which uses the association with PingPlotter to find PingPlotter and run it. The final parameter isn't used by the association, so it's discarded. That's just like double-clicking on a .pp2 file, it just loads.
So what you need to do is to stick in a dummy window title at the beginning, something like this:
START "PingPlotter Window Title" "C:\Program Files\Ping Plotter\PingPlotter" "C:\Program Files\Ping Plotter\comcast.pp2" /TRACE
The opening title can be an empty one too (i.e., ""), but I inserted the title there to make it easier to pick up.
- Pete