For VB Plugins you have to load it the same way Plus! does. Thats why for VB Plugins you have to put in the registry Projectname.Classname. Thats how they are loaded from Plus! since VB Plugins alone don't export their functions.
This is for VB not sure about C++
What you can do is Enum through the RegisteredPlugins section and CreateObject() for the Projectname.Classname
Then call configure.
code:
Private Sub Form_Load()
Dim Plugin As Object
Set Plugin = CreateObject("%Projectname%.%Classname%")
Plugin.Configure
End Sub