how to add custom properties of doc file from database

protected void CreateWord()
        {
            AdminActivityBL objAdminActivity = new AdminActivityBL();
            objAdminActivity.SaveCreateWord();

            object fileName = "D:\\MyWord.dotx";
            object novalue = System.Reflection.Missing.Value;
            Microsoft.Office.Interop.Word.Application objWord = new Microsoft.Office.Interop.Word.Application();
            Microsoft.Office.Interop.Word.Document objWordDoc = objWord.Documents.Add(ref novalue, ref novalue, ref novalue, ref novalue);

            objWordDoc.Activate();
            DataSet ds = new DataSet();
            ds = objAdminActivity.GetAddTemplateDetails(objTemplate);
            DataTable table = ds.Tables[0];
            DataRow row = table.Rows[0];

            foreach (DataRow dr in table.Rows)
            {
                object oDocCustomProps = objWordDoc.CustomDocumentProperties;

                Type typeDocCustomProps = oDocCustomProps.GetType();

                string name = string.Format("{0}", dr["AttrName"]);
                string value = string.Format("{0}", dr["AttrValue"]);
                string type = string.Format("{0}", dr["AttrType"]);


                object[] oArg = 
                { 
                    name, 
                    false, 
                    Microsoft.Office.Core.MsoDocProperties.msoPropertyTypeString, 
                    value 
                };

                typeDocCustomProps.InvokeMember("Add", BindingFlags.Default | BindingFlags.InvokeMethod, null, oDocCustomProps, oArg);

                objWord.Visible = true;

              }
           



            objWordDoc.SaveAs(ref fileName, ref novalue, ref novalue, ref novalue,
                        ref novalue, ref novalue, ref novalue, ref novalue, ref novalue,
                        ref novalue, ref novalue);

            //objWord.Quit(ref novalue, ref novalue, ref novalue);

          }

public DataSet GetAddTemplateDetails(Template objtemplate)
        {
            AdminActivityDB objAdminActivityDB = new AdminActivityDB();
            return objAdminActivityDB.GetAddTemplateDetails(objtemplate);
        }

public DataSet GetAddTemplateDetails(Template objTemplate)
        {
            Database objDB = new SqlDatabase(ConfigurationHelper.ConnectionString);
            using (DbCommand objCMD = objDB.GetStoredProcCommand(GET_ADDTEMPLATE_DETAILS))
            {

                objDB.AddInParameter(objCMD, "@TemplateId", DbType.Int32, objTemplate.TemplateId);
                DataSet retDS = objDB.ExecuteDataSet(objCMD);
                return retDS;

            }
        }