How to change the text of a bookmark in a Word document without deleting it?

Question

C++ / C#

In this example, the bookmark is removed, replaced with text. Tell me how to replace the text of the bookmark without deleting it?

string fileName = "Имя_файла.docx";
wordApp = new Word.Application();
document = wordApp.Documents.Open(fileName);
Word.Bookmarks bookmarks = document.Bookmarks;

bookmarks["Дата"].Range.Text = DateTime.Today.ToShortDateString();
bookmarks["Номер"].Range.Text = "12345";

document.Close();
document = null;
wordApp.Quit();
wordApp = null;