I work for a .NET/MSSQL shop that has trouble supporting customers running Novell, partially because we don't have Novell (or the money for it) and partially because we have no one with Novell experience. This question could easily be expanded to "How can we improve our support of technology X when we don't have technology X?" Obviously, I expect someone to say "it is easy to acquire the technology or someone with that kind of experience," but keep in mind I'm just a developer, not the development manager or someone with power over the purse strings. I looked for a Novell server virtual appliance (though I'm not sure "Novell server" is what I should be looking for) but didn't find much on VMware's website.
There is a 60 day evaluation trial of Open Enterprise Server 2 available (requires free registration). If you install it in a VM, there's nothing stopping you from reinstalling it after 60 days (well except licence).
But you will need someone good with Linux to handle this (and preferably good with this precise technology). In a MS shop this might be a problem.
The easiest solution would be to outsource this - have some external techs test your software for compatibility. If you find out you are paying too much - hire someone who knows this software stack.
You can't support something if you don't test against it. And you can't test against something you don't know.