Thanks for the suggestion... tried it, but it didn't work. (Maybe something else I got wrong? Once again, I could browse to it on the browser and it offered to download the file, but the browser did not seem to pick it up as a wpad.dat file.)
From
http://www.wrec.org/Drafts/draft-cooper-webi-wpad-00.txt (one of the many sites I visited trying to find a solution :-)), it seems to indicate that it goes down (or up?) the domain name tree looking for wpad.dat files as it goes (but I could be misreading it...)
An excerpt is below... but first, another question which is sort of related (and will show my lack of knowledge on the subject).
Say I have a domain, mydomain.com, which is a real "external" domain with email and web sites hosted elsewhere... If I am setting up a local (or internal) domain (which is not really connected to mydomain.com, other than in name only)... is it wise to use private.mydomain.com or internal.mydomain.com (etc), or should I just make up some other internal domain name? In the future, who knows, I might host some of the real "mydomain.com". This may not be the forum to ask, but I am not sure where I should ask these rather basic, yet quite fundamental, questions (feel free to point me in a more suitable place to ask such questions).
Now the exert from the Web Proxy Auto-Discovery Protocol link above...
As an example, consider a client with hostname
johns-desktop.development.foo.com. Assume the web client software
supports all of the mechanisms listed above. This is the sequence of
discovery attempts the client would perform until one succeeded in
locating a valid CFILE:
o DHCP
o SLP
o DNS A lookup on QNAME=wpad.development.foo.com.
o DNS SRV lookup on QNAME=wpad.development.foo.com.
o DNS TXT lookup on QNAME=wpad.development.foo.com.
o DNS A lookup on QNAME=wpad.foo.com.
o DNS SRV lookup on QNAME=wpad.foo.com.
o DNS TXT lookup on QNAME=wpad.foo.com.