Ok then, what you have to do is to find out whats beneath the plastic......the chances are its stuck directly onto the wall, but who knows?
You need to do a test drill in an inconspicuous area......behind a mirror or somewhere else nicely discreet.
If your luck is in, you should find that a 6mm rawlplug tapped well into the drilled hole should hold well - it doesn't matter if the head of the plug is below the surface of the plastic, so long as the plug itself is firm into the wall behind.
John