This example adds WordArt that contains the text "Test" to myDocument
and rotates the characters 90 degrees counterclockwise.
Set myDocument = ActivePresentation.Slides(1)
Set newWordArt = myDocument.Shapes.AddTextEffect _
(PresetTextEffect:=msoTextEffect1, Text:="Test", _
FontName:="Arial Black", FontSize:=36, _
FontBold:=False, FontItalic:=False, Left:=10, Top:=10)
newWordArt.TextEffect.RotatedChars = True