Sub Textboxnew()
    Dim myTextBox As Shape
    With ActivePresentation.Slides(1)
        Set myTextBox = .Shapes.AddTextbox _
            (Orientation:=msoTextOrientationHorizontal, Left:=450, Top:=20, _
            Width:=100, Height:=100)
        myTextBox.TextFrame.TextRange.Text = "NEW"
        myTextBox.TextFrame.TextRange.Font.Color.RGB = vbRed
        myTextBox.TextFrame.TextRange.Font.Size = 20
    End With
End Sub