VisView is the application from EAI that supports team interaction on engineering drawings, correct? If so, have you tried the support on the EAI website [eai.com]?
Not being familiar with the particulars of the application makes me hesitate to take a guess. I assume that there must be a client plug-in or application of some kind involved in opening a VisView file and that you are developing a "private membership" website or intranet of some kind so you can assume everyone has the needed software.
Normally Windows needs a file extension to recognize which application to launch, and you've stated that the files you're working with are strings of numbers and hyphens, with no extension. But honestly, that's just a conjecture, and may not apply in this case.
Maybe a member here has worked with this application and can give you a more precise direction. We have a lot of members with very diverse knowledge. So I'm floating the thread to give your question some more attention.