[Opserty]

I don't know how Verotel works or even what it is but I'm guessing that there must be some kind of data stored in a database somewhere. You could create a (cron)script which updates the users usergroup from a normal member to a authenticated member, or something of the sort.

I think the problem is you are trying to draw a line between two different installations but this line isn't between the actual directories its inside the files in the directory. Try working with vB's in-built features and use them to your advantage instead of trying to go to the extra hassle of major editing of files & other things.