Thank you for your answer. I did search for a link a bit, but didn't find one.
I hoped there is a way like this (in pseudo-code):
OPEN URL "http://epaper.derstandarddigital.at/";
coverElement = (SEARCH HTML-ELEMENT "<img>" WITH ID "imgPage2" AND CLASS "page");
coverUrl = (GET HTML-ATTRIBUTE "src" FROM coverElement);
Wouldn't that be a way?