I like to add few things here. Text highlighting feature is currently not supported. Please visit this thread link for your further kind reference. In order to SubScript or SuperScript text, please use Portion. Escapement property. In case of PPTX, please use PortionEx.PortionFormat. Escapementproperty. Its default value is 0 and sets text as normal text. Its value ranges from -100 to 100. -100 being maximum value for SubScript and 100 being maximum value of SuperScript. Please share if I may help you further in this regard.