Net 2.0 How to Import Usercontrols with ImportCatalogPart in vb.20

[Basman]

I am trying to find out how to Import User Controls as Webparts using
ImportCatalogPart and the steps necessary to do this. These will not be
Webparts in Sharepoint. They will be strickly in the Net 2.0 Framework as
Webparts coded in VB.

I know how to use a UserControl when its wrapped in a GenericWebPart and
included as part of the solution.

Instead I plan on creating a catalog of user controls(20-30 at least) that
the users can select from residing on the server and choose which to use.

I have seen examples of the code needed to create a xml dynamic catalog.

What I need to know/find is the form(ascx/dll/...?) the User Control takes
to be able to put it on the server and have it be able to be Imported. The
User Control will access out database using webservices so I don't believe it
can left as an ascx file since that would not contain the location reference
to the webservices. I'm trying to figure if that means the user control must
be in some type of library or dll to have all the associated references it
needs.

Does it need to be made into a DLL and exported to make a .webpart file and
then imported?

Are there any articles that show how to accomplish this. Nothing I have seen
shows how to import UserControls as webparts in the ImportCatalogParts, only
how to generical wrap them when they are part of the Web Solution.