adding dll reference into managed C++ visual studio 2008 project

[arfte]

Hi, guys
If you open http://support.microsoft.com/kb/310674 link, you will see there are several ways that make using references in a Managed C++ application.
I tried all of them, but i still cannot see the object of the dll reference project.
My project is a mixed mode project which contains normal C++ MFC classes and a managed C++ class which communicates with external dll objects.
From my managed C++ class I am going to add the dll reference which contains many classes and objects from another project.
I am able to register the dll file and create tlb file but with including those dll or tlb file in my manged C++ class i still cannot seethe external objects.
Then, i tried to create an interop assembly for a COM object, using the TLBIMP.exe tool, i get the following errors.
tlbimp externalobj.dll /out:Interop.externalobj.dll
"TlbImp : error TI0000 : The input file externalobj.dll is not a valid type library."

Anybody had the same problems and solved it or knows what the problem is, please teach me.
Thanks.
- james