During the last meeting, I mentioned something about a function within LabVIEW that can be used to read what data type a Variant's value was originally, but I couldn't remember the name. Today I came across it, so I figured I would show it here to prove I wasn't dreaming things!
The function is called 'Get Type Information' and is part of NI_Data Type.lvlib. If you wire a variant to it you will get some information about the variant including the data type of the data contained therein. This way you can make sure your parsing succeeds. In older versions of LabVIEW, a VI that effectively does the same thing is in the 'VariantType.lvlib' library and is called 'Get Type Info.vi' (though you might have to go to vi.lib directly to dig this one out).
Hope this helps someone!