Using a .NET 4.0 DLL in Unity3d via COM/SxS?

In an attempt to oversimplify my issue, I'll try to keep it short:

I'm using the pro version of Unity, and I have 2 DLLs:

1. A .NET 3.5 assembly (acting as a COM client)
2. A .NET 4.0 assembly (with an interface exposed via COM)

The 3.5 uses COM to work with the 4.0. Using the 3.5 assembly in a Windows app works fine, it loads the 4.0 dll using SxS via Type.GetTypeFromCLSID() or Type.GetTypeFromProgID() (which I've confirmed with SxStrace), and can use it's functionality just fine. (The windows app mentions it's dependency on the 4.0 DLL via a manifest, I'm not registering the COM DLL.)

I'm trying to use the .NET 4.0 DLL in Unity. Obviously I can't use it directly, since the current flavor 开发者_Go百科of Mono that Unity uses only supports up to 3.5, thus I created the 3.5 assembly to be my middleman. I'm able to use the 3.5 assembly fine in unity, but either of the Type methods I mentioned before throw NotImplementedException(s), as apparently they aren't supported by Unity (or rather, Mono), so I'm at a loss.

Any ideas?

Although this question was made 1 year ago..sadly the middleman tactic still wont work, it is not possible to use .NET 4.0 dlls within Unity3D since Mono is just not supporting the dependencies. You could try to remove any 4.0 dependencies from the dll and compile it as 3.5, if that is possible for you.