how to convert following vb code into c#

Private Sub Command1_Click()
    Dim MyWord As Word.Application, WordDoc As Word.Document

    Set MyWord = New Word.Application
    Set WordDoc = MyWord.Documents.Add

    AddWaterMark WordDoc

    MyWord.Visible = True
End Sub


Private Sub AddWaterMark(pDoc As Word.Document)
    pDoc.Shapes.AddTextEffect 0, "ULTRA SECRET", "Century Gothic", 1, False, False, 0, 0
    pDoc.Shapes(1).Name = "PowerPlusWaterMarkObject1"
    pDoc.Shapes(1).TextEffect.NormalizedHeight = False
    pDoc.Shapes(1).Line.Visible = False
    pDoc.Shapes(1).Fill.Visible = True
    pDoc.Shapes(1).Fill.Solid
    pDoc.Shapes(1).Fill.ForeColor.RGB = RGB(0, 255, 255)
    pDoc.Shapes(1).Fill.Transparency = 0.8
    pDoc.Shapes(1).Rotation = 315
    pDoc.Shapes(1).LockAspectRatio = True
    pDoc.Shapes(1).Height = 80
    pDoc.Shapes(1).Width = 520
    pDoc.Shapes(1).WrapFormat.AllowOverlap = True
    pDoc.Shapes(1).WrapFormat.Side = wdWrapNone
    pDoc.Shapes(1).WrapFormat.Type = 3
    pDoc.Shapes(1).RelativeHorizontalPosition = wdRelativeVerticalPositionMargin
    pDoc.Shapes(1).RelativeVerticalPosition = wdRelativeVerticalPositionMargin
    pDoc.Shapes(1).Left = wdShapeCenter
    pDoc.Shapes(1).Top = wdShapeCenter
End Sub