Материал из .Net Framework эксперт
Set word document style
using System;
class MainClass {
private static object n = Type.Missing;
static void Main(string[] args) {
Word.ApplicationClass app = new Word.ApplicationClass();
app.DisplayAlerts = Word.WdAlertLevel.wdAlertsNone;
Word.Document doc = app.Documents.Add(ref n, ref n, ref n, ref n);
Word.Range range = doc.Paragraphs.Add(ref n).Range;
range.InsertBefore("Test Document");
string style = "Heading 1";
object objStyle = style;
range.set_Style(ref objStyle);
range = doc.Paragraphs.Add(ref n).Range;
range.InsertBefore("Line one.\nLine two.");
range.Font.Bold = 1;
doc.PrintPreview();
app.Visible = true;
}
}