From what I can tell, it's not possible to play back an HD-DVD rip off a network drive. 
Whilst you can do it fine if you've ripped a movie onto your local hard drive using anydvdhd, if you save it on a remote PC / server, when you go to PowerDVD Ultra and select play back movie files from hard drive, it will allow you to select the movie (the root directory before the HVDVD one) but when you click on OK, there's an error message which pops up:
I've contacted Cyberlink about this and the answer was unfortunately not very promising:
Well, sounds like they won't even support having an HD-DVD image on your local hard drive, let alone a remote one.
So in my aim to have a "back room server" with all my HD-DVDs on it, I'm now stifled
Anyone else played around with network-shared HD-DVD images and found a workaround?
A bit annoyed now. The cost of the software (PDVD) isn't exactly cheap and I can't even use it for what I bought it for
Whilst you can do it fine if you've ripped a movie onto your local hard drive using anydvdhd, if you save it on a remote PC / server, when you go to PowerDVD Ultra and select play back movie files from hard drive, it will allow you to select the movie (the root directory before the HVDVD one) but when you click on OK, there's an error message which pops up:
FSE_FAILED: Failed to Open
the File. Using file ""
I've contacted Cyberlink about this and the answer was unfortunately not very promising:
Cyberlink said:Thank you for contacting Cyberlink Online Customer Support.
We understand that you are getting error when try to play the HD-DVD files from harddrive.
In regards to your issue, we regret to inform you that PowerDVD Ultra can support playback of HD-DVD's from DVD drive directly, not form harddrive.
It could be the reason for your issue.
Well, sounds like they won't even support having an HD-DVD image on your local hard drive, let alone a remote one.
So in my aim to have a "back room server" with all my HD-DVDs on it, I'm now stifled
Anyone else played around with network-shared HD-DVD images and found a workaround?
A bit annoyed now. The cost of the software (PDVD) isn't exactly cheap and I can't even use it for what I bought it for