using DevExpress.XtraRichEdit.API.Native;

using (var wordProcessor = new RichEditDocumentServer())
{
  wordProcessor.LoadDocument("Document.docx");
  Document document = wordProcessor.Document;

  // Obtain the third paragraph:
  DocumentRange hiddenRange = document.Paragraphs[2].Range;
  CharacterProperties hiddenTextProperties =
    document.BeginUpdateCharacters(hiddenRange);

  // Mark the paragraph as hidden:
  hiddenTextProperties.Hidden = true;
  document.EndUpdateCharacters(hiddenTextProperties);
}

Imports DevExpress.XtraRichEdit.API.Native

Using wordProcessor = New RichEditDocumentServer()
  wordProcessor.LoadDocument("Document.docx")
  Dim document As Document = wordProcessor.Document

  ' Obtain the third paragraph:
  Dim hiddenRange As DocumentRange = document.Paragraphs(2).Range
  Dim hiddenTextProperties As CharacterProperties =
    document.BeginUpdateCharacters(hiddenRange)

  ' Mark the paragraph as hidden:
  hiddenTextProperties.Hidden = True
  document.EndUpdateCharacters(hiddenTextProperties)
End Using