App.Config custom configuration helper not instatiating

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C#

I'm being trying to setup a custom section in my app.config for a COM object I'm building with no luck, after spending a couple days; yes a couple of days; looking at sample code explanations from different forums I still cannot make it work. This is a simplified code I put together to describe the issue:

ConfigurationTest.cs

using System.Runtime.InteropServices;
using System.Configuration;

namespace configurationTest
{
    [ClassInterface(ClassInterfaceType.AutoDual)]
    [ProgId("Utils.ConfigurationTest")]
    public class ConfigurationTest
    {
        public string passWord = "";

        public ConfigurationTest()
        {

        }

        public string getPassword()
        {
            configurationHelper config = (configurationHelper)ConfigurationManager.GetSection("credentials");
            this.passWord = config.PassWord;
            return this.passWord.ToString();
        }
    }
}

ConfigurationHelper.cs

using System.Configuration;

namespace configurationTest
{
    public class configurationHelper : System.Configuration.ConfigurationSection
    {
        [ConfigurationProperty("passWord")]
        public string PassWord
        {
            get { return (string)this["passWord"]; }
            set { this["passWord"] = value; }
        }
    }
}

app.Config

<?xml version="1.0" encoding="utf-8" ?>
<configuration>

  <configSections>
    <section name="credentials" type="configurationTest.configurationHelper, ConfigurationHelper"/>
  </configSections>

  <credentials passWord ="PDm!@M!11"/>

</configuration>

My problem is when I instantiate the COM object and call the getPassword method the variable "config" is null. What am I doing wrong? any ideas are welcome,

Thank you