Delete character in Microsoft word + vb.net

Imports Microsoft.Office.Interop.Word
Imports Microsoft.Office.Interop
Imports Microsoft.Office

Public Class classWord

    Public Sub GetWord()

        Dim WdApp As New Application

        Dim WdDoc As Word.Document

        WdDoc = WdApp.Documents.Open("D:\text.doc")

        Dim rStart, rStop As Integer

        rStart = 100

        rStop = 200

        WdDoc.Range(Start:=rStart, End:=rStop).Delete()

        WdDoc.Save()

        WdDoc.Close()

        WdDoc = Nothing

        WdApp.Quit()

        WdApp = Nothing

    End Sub

End Class