Calling .NET module from LabVIEW

Hi, 

I'm a beginner of LabVIEW.  

I straggled with calling .NET module from LabVIEW, but I couldn't.  I just wired create instance->method invoke->complete and the code became executable, but an error occurred when the wired program was executed.  (The module returned "E_FAIL")

I would like to call COM interfaces inside the module, but is it possible to call them?  I also tried to call COM interfaces directly inside the module by using "Library Function Calling Node", but I couldn't find the interfaces in the list of methods.  

I look forward to your reply.  

Thanks,

Hideki