I am facing a similar problem. and Qliktech suggested to create two web server. one for internal users and other for extrenal.
But the problem is they have told us to install only QV Webserver on differnet machine.
I am not able to uplaod the document if you can provide your email id i will send it across to you. I am not able to figure it out the best possible way to acheive the same.
Because installing the webserver into a new machine again creates a cost for us.
Hope we all can sort it out in a best possible way