Trying to get access to my web camera connected to the USB-port on my wl-500g from internet

The manual does not say much about how to set up this. I want to access the camera without using any logon to the router. The camera is a Locitech QuickCam 4000 Pro, and works on my internal network (but I still have to log on the router). So my question is as follows:

* How to set up the router so it is possible to reach it from internet
* The access to the camera should not need any logon (or at least an account different from Admin)
* The syntac of the address to type when I'm on a computer on internet