Hi,
Since CVI is a C programming language it will not be able to call methods or access members in a exported class. Probably the easiest way to get around this, is to create a wrapper DLL in a language that can access exported classes.
Basically you create a C exported function in the wrapper DLL that calls the method that you want to access in the .NET DLL. At the end you have a DLL that exports a C function for every method in the .NET DLL.
I hope this helps!
Regards,
Juan Carlos
N.I.