let PFormat = ActivePresentation.Slides.Item(1).Shapes.Placeholders
if(PFormat.Count > 0){
    let PFormat1 = PFormat.Item(1)
    switch(PFormat1.PlaceholderFormat.Type){
        case ppPlaceholderTitle:
            PFormat1.TextFrame.TextRange = "Title Text"
            break
        case ppPlaceholderCenterTitle:
            PFormat1.TextFrame.TextRange = "Centered Title Text"
            break
        default:
            MsgBox("There's no horizontal "+"title on this slide")
    }
}