HELP WITH VB.NET AND AutoCAD! Are there out there any gurus?

It seems like this is a very difficult question or not too many people
have come to the challenge of using VB.NET for programming autocad.

I have a very common scenario for VB6 autocad programmers. I want to
have a VB.NET DLL with a form in it, and a client application VB6 or
VB.NET I dont care (but I prefer VB.NET). Then in my client I
reference autocad application, I use application.GetInterfaceObject to
inject my DLL in autocads memory space and call a function of my DLL
from the client that shows the DLL's form.
In this way, as VB6 autocad programmers know, the DLL's form is shown
modally "within" autocad.

Well I have done this many times in VB6, I just cant accomplish it
using a VB.NET Dll with a form in it!!!!

PLEASE!!! is there someone who has tried this out and knows whats
going on???
The whole thing is to make my form in VB.NET, I dont care if the
client is in VB6 or .NET or whether I will use COM or not... I just
want to accomplish the same VB6 scenario with VB.NET form....

(I have tried a couple of things but none behaves the exactly like the
VB6 scenario)

Thank you, I will appreciate any help on the subject
Elias