Can "Do Visual Basic" call functions in an add-in?

I’m using Applescript from a Cocoa app to call functions in a PowerPoint presentation written in VBA.

Works great.

Then, I save the PowerPoint presentation as a PowerPoint add-in and install the add-in.

The toolbar that I created from VBA comes up. Everything seems to be working fine.

But when I try to call one of the VBA functions using “do Visual Basic (“Call functionX”)” from Applescript. It doesn’t work.

I try it from Script Editor, and am told that "Call functionX" doesn't understand the "do Visual Basic" message.

So, I'm guessing that once I turned the VBA code into an add-in, it was compiled or something and was no longer VBA code. Or maybe calling VBA code through Applescript is specific to a presentation that the VBA code resides in, but when it's an add-in it's not a part of the presentation, but rather lives at the application level, and thus perhaps is inaccessible from Applescript?

Any insights would be greatly appreciated.