Sets or returns a Font.UnderlineType object that represents the underline type for this formatting.

 public UnderlineType Underline{ get; set; }
Public Property Underline() As UnderlineType

MS Word equivalent: Format menu > Font... > Font tab > Underline style:

          //--- Return Underline
          Font.UnderlineType oUnderline = oFont.Underline;

          //--- Set Underline to Double
          oFont.Underline = Font.UnderlineType.Double;
        
          '--- Return Underline
          Dim oUnderline As Font.UnderlineType = oFont.Underline

          '--- Set Underline to Double
          oFont.Underline = Font.UnderlineType.Double