I confirm that you cannot find the root directory of a snapshot view only knowing its view tag: a snapshot view can be loaded in several separate directories if you want.
The only link between your snapshot view and its root directory is the .view.dat hidden file which contains the uid of the view.
Plus, the hostname attached to a view has nothing to do with the fact it is loaded or not on a computer. It is the name of the view server (which can be your own desktop, or can be a centralized server). It is on that server that the view.exe process managing all ClearCase-related operations for that view.
So, with your script (like for instance a perl script), you don’t really need CAL at first to find that view: you need first to be able to look the the view.dat file, extract the uid, and then check if it is the same than the view uid (lsview -l -full -pro) you are looking for.