Read word document proprties

string filePath = "c:\\docprop.doc";
object file = filePath;
object nullobj = System.Reflection.Missing.Value;
Word.Document oDoc = oWord.Documents.Open(ref file, ref nullobj, ref nullobj, ref nullobj, ref nullobj, ref nullobj, ref nullobj, ref nullobj, ref nullobj, ref nullobj, ref nullobj, ref nullobj, ref nullobj, ref nullobj, ref nullobj, ref nullobj);

oDocBuiltInProps = oDoc.BuiltInDocumentProperties;