You were looking in the wrong place.
On page https://github.com/coherence-project/UPnP-Inspector at Installing pre-build packages there is a link to a windows executable download. It doesn't work on my XP computer! You would need to source a new(er) version of libcairo-2.dll (probably from an unreputable source) to get UPnP Inspector to work. I did. It works. But, to be honest, I find this program to be of no use whatsoever.
Ta. Sounds like I could be getting into the world of endless pop ups and dodgy sites! Any other ways you know of finding the url of a file on the Hummy? I'm sure (like I can on Win 10 media player) that all I'll need to do is copy the url into Chrome?
Despite foobar2000 being an audio player then as I said above if you download it https://www.foobar2000.org/download and the foo_upnp add-in https://www.foobar2000.org/components/view/foo_upnp you can get it to do what you want.
With foo_upnp added, from the View menu there is UPnP Browser option which pops up a window showing servers, click on HDR media server item and it should give you a My Video list - browse this and the folder contents shown in the other window, find & select your file and then right click - pop up shows list including File Operations. Copy to will probably do what you want. If you don't do anything else to it, chances are that you will end up with a file such as 5142.ts in your "My Documents" directory on the PC even if the file you browsed was called "Star Trek_ The Next Generation_20180614_1858.ts"