It is not essential that you have it connected to your router/computer network/internet, but there is little point in installing the custom software if you cannot access the HDR from your computer. All the shuffling about of programs etc. is done via a web interface served by the custom software on the Hummy. I suggest that you do a bit of reading. Download the software and read the readme several times until you understand it and then read it again.
of the main brilliant 'culprits' for it, raydon and others, are also active on this site and generally help out newbies, so long as they have read the stuff that he has written about it and don't ask questions that he has already answered.
It is easy to install, and once you have connected your Hummy to your computer there are wondrous things that you can do with it. One of which, is exactly what you want to be able to do. You cannot do it without the custom software though.