With help from the forum I managed to edit the configure.php file. I uploaded it, changed the permissions, correctly I think.
Now when I try the url http://my dom/my newfile/
I get a 404 page. I cannot find anything in the faq's and I can't find the original page that lead me to the tutorial page telling me to edit configure.php. So I am firmly at a brick wall. I don't know what the next step will look like or do.
I can log in the zencart page. Just no idea what to do.