public partial class MainWindow : Window
    {
        object nomeFile = "C:\\Id.dot";
        WORD.Application objWord;
        WORD.Document objDoc;

        ADODB.Connection cn = new ADODB.Connection();
        ADODB.Recordset rs = new ADODB.Recordset();        

        string cnstr = " miaStringaDiconnessione ";
        string query = " miaQuery ";


        public MainWindow()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, RoutedEventArgs e)
        {       
     
          cn.Open(cnstr,null,null,0);
            rs.Open(query, cn, ADODB.CursorTypeEnum.adOpenKeyset,ADODB.LockTypeEnum.adLockOptimistic,-1);
            rs.Close();
            cn.Close();

            objWord = new WORD.Application();
            objWord.Visible = true;

            objDoc = new WORD.Document();

            objDoc = objWord.Documents.Open(ref nomeFile);
            objDoc.Activate();


                foreach (WORD.FormField aField in objDoc.FormFields )
                {
                    aField.Result = (rs.Fields[aField.Name]).ToString();                   
                }

                objWord.ActiveDocument.Fields.Update();
                objWord.Documents.Save();          
           
        }