How not to count page numbers for hidden slides in PPT?

Thank you Steve. I found an answer to my question elsewhere. The function below allows you to avoid that hidden slides are interfering with the slide numbers of unhidden slides in presentation mode.

Sub Number_NonHidden()
'For v.2007 onwards only
Dim osld As Slide
Dim objSN As Shape
Dim lngNum As Long
'check all slides
For Each osld In ActivePresentation.Slides
'Is it hidden
If osld.SlideShowTransition.Hidden Then
osld.HeadersFooters.SlideNumber.Visible = False
Else
osld.HeadersFooters.SlideNumber.Visible = True
Set objSN = getNumber(osld)
lngNum = lngNum + 1
If Not objSN Is Nothing Then ' there is a number placeholder
objSN.TextFrame.TextRange = CStr(lngNum + 1)
End If
End If
Next osld
End Sub

Function getNumber(thisSlide As Slide) As Shape
For Each getNumber In thisSlide.Shapes
If getNumber.Type = msoPlaceholder Then
If getNumber.PlaceholderFormat.Type = ppPlaceholderSlideNumber Then
'it's the slide number
Exit Function
End If
End If
Next getNumber
End Function

In order to avoid that the title slide is numbered insert lngNum = -1 as follows and delete the slide number box in the master title slide.

'check all slides
lngNum = -1
For Each osld In ActivePresentation.Slides