How to write slide page in vba

Question

I am creating the slidemaster in vba for a ppt presentation and in one of the text boxes that I am creating I want to write the slide number, but I am unable to find the function that allows me to do it. Can someone help me?

'page
Dim pageslide As Object
Set pageslide = ppSlide.Shapes.AddShape(msoTextOrientationHorizontal, 700, 500, 220, 30)
With pageslide
    .Fill.Transparency = 1
    .Line.Visible = msoFalse
    With pageslide.TextFrame.TextRange
        .Text = 'O QUE DEVO ACRESCENTAR AQUI?'
        .ParagraphFormat.Alignment = ppAlignLeft
        .Font.Size = 9
        .Font.Name = "Calibri"
        .Font.Color = RGB(256, 256, 256)
    End With
End With