When you call a VI via ActiveX, the controls names in the paramnames array list must be on the connector pane, e.g. they are inputs controls that you can wire from a diagram. Also, all inputs that are set "required" on the connector must be set in the paramnames array. Failing to do that will generate connector panes errors.
A built application can also be an ActiveX server. In the application builder settings, check the box to activate the ActiveX server and give it a name, say "myapp". Do not use "labview" of course... In VB you create an reference to your built app using CreateObject("myapp.application")