Determine that Variant is a VISA refnum?

[Mike Matthes]

I'm trying to figure out if there is a fixed type descriptor for a VISA refnum type of Variant. It's easy enum to determine types that are listed in NI's documentation, such as SGL, DBL, etc, but when you get to hex 70, it is a "refnum". There are tons of different types of refnums available, but I need to know if it is a VISA refnum so I can handle it differently. I have a solution where I just try to convert the variant back to a VISA - if it works it must be a VISA refnum, if it fails it must not be. That's kindof a shotgun approach. Does anyone know the secret decoder for the refnum subtypes? I haven't been able to find a document on this.

Thanks!