'This procedure looks on a slide for shape 2. That shape contains the numbers of other
'slides. It randomly picks one of those numbers to jump to.
Sub ChooseNext()
    Dim numChoices
    Dim randChoices As Long
    Dim randNext As Long
    
    Randomize (Timer)
    
    numChoices = ActivePresentation.SlideShowWindow.View.Slide.Shapes(2).TextFrame.TextRange.Words.Count
    'MsgBox numChoices
    If numChoices = 0 Then
        MsgBox "The End"
        ActivePresentation.SlideShowWindow.View.Exit
    Else
        randChoices = Int(Rnd * numChoices) + 1
        'MsgBox randChoices
        randNext = ActivePresentation.SlideShowWindow.View.Slide.Shapes(2) _
            .TextFrame.TextRange.Words(randChoices)
        'MsgBox randNext
        If randNext > ActivePresentation.Slides.Count Then
            MsgBox "Sorry, there is an error."
        Else
            ActivePresentation.SlideShowWindow.View.GotoSlide randNext
        End If
    End If
End Sub