Passing variables by VBA between excel and visio in early binding

I control MS Office.Visio from Excel, using early binding, to manipulate Visio pages, shapes etc.  Thus far, the superior scope for RibbonX customisation in Excel has given me control over customised processes in Visio, that greatly exceeds the customisation provided by the visio ribbon.

However, I now need to control the occurrence of specific RibbonX custom tabs in Excel, by detecting change events triggered by changes in the current Visio.activePage.

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VisioGuy (EE) provided me with code that detects change events in visio active page, when placed in the visio document code sheet:

Dim WithEvents m_visWins As Visio.Windows
Private Sub Document_RunModeEntered(ByVal Doc As IVDocument)

  Set m_visWins = Visio.Application.Windows

End Sub

Private Sub m_visWins_WindowTurnedToPage(ByVal visWin As IVWindow)

  If (visWin.Type = Visio.VisWinTypes.visDrawing) Then
    Debug.Print "WindowTurnedToPage: " & visWin.Page  '<<<<<<<<<<<
  Else
    Debug.Print "WindowTurnedToPage, but not a drawing window: " & visWin.Caption
  End If
 
End Sub
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This code works well in visio but, perhaps not surprisingly, does not capture the Visio event when the code is placed the worksheet code page of an excel workbook that has been set to reference the visio object model (via VBE/Tools/References).

How do I monitor in excel,  visWin.Page (marked '<<<< above) as an object or as a string = object.Name

- can I use a public variable in visio, and make it detectable in excel (my attempts have failed so far)
- do I create a new class in visio, and attempt to detect visio page changes as a property of the visio object model?
- do I try to use the Application.Run Method inserted in code at the point marked '<<<< (above) and pass variables as arguments by position. I understand Application.Run arguments cannot be objects, but I could live with that, if it works for other variables).
- or something else?

- IF POSSIBLE! it would be helpful to have one generic method that can be used to pass variables in either direction between Excel and Visio, to transmit other variables in the future. Given that Visio macros are stored as documents, and hence called by ...ExecuteLine("myMacro"), would a bidirectional method be impossible?

Some pointers to start me off would be appreciated..

Thanks!