[Paraview] how to control paraview from python

[Jorge Mario Mazo]

Hi there

I have a python script that does a lot of stuff to some vrml files, it
works perfect if its ran from the paraview python shell,
but when I run it from outside paraview, the script runs, but it does
not visualizes anything. I dont how to tell python to use the
"open" paraview.
I also tried to create a server pvserver, connect my script to that
server and then I opened paraview and connected it to that server

but I keep getting

"The startup command failed to start ... check your PATH and file permissions"

what should my PATH have?

thanks in advance