I am also having a problem creating a star wingding in version 5.2.0. The ascii code for the character is 171. I am also getting double arrows on the output of the .ppt instead of what should be a star. Below is the code that I created:
Dim oFontEnitity As New FontEntity(pres, pres.Fonts(0))
oFontEnitity.CharSet = FontCharSet.SYMBOL_CHARSET
oFontEnitity.FontName = "Wingdings"
Dim rawSymbolFontIndex As Integer
rawSymbolFontIndex = pres.Fonts.Add(oFontEnitity)
Dim sStarString As String
Dim istar As Integer = &HAB
sStarString = Char.ConvertFromUtf32(istar)
oRect = slide.Shapes.AddRectangle(50, 50, 100, 100)
oRect.LineFormat.ShowLines = False
oTxtFrame = oRect.AddTextFrame(sStarString)
oTxtFrame.Paragraphs(0).Portions(0).FontColor = System.Drawing.ColorTranslator.FromHtml("#9F9F9F")
oTxtFrame.Paragraphs(0).Portions(0).RawSymbolFontIndex = rawSymbolFontIndex