Range.EmphasisMark (Word)

Returns or sets the emphasis mark for a character or designated character string. Possible return values are wdEmphasisMarkNone - No emphasis mark, wdEmphasisMarkOverComma - A comma, wdEmphasisMarkOverSolidCircle - A solid black circle, wdEmphasisMarkOverWhiteCircle - An empty white circle, wdEmphasisMarkUnderSolidCircle - A solid black circle.

ActiveDocument.Words(4).EmphasisMark = wdEmphasisMarkOverComma