What's the BEST method for installing the client on XP machines with
limited rights via the Novell Login script?

Customer does not have any ZEN/NAL in place yet.

(otherwise then I'd know how to do it).

I know that you can use a GPO in AD to deploy software, but I think it
requires that you use .MSI Files (which apparently doesn't exist in the
ZEN 7 Suite with SP1).