Validate "custom" properties

[StringLengthVerifier(MaxValue = 20, MinValue = 6, IsRequired = true, ErrorMessage = "Password Required")]

I'm trying to make my partial class to play nicely with verification engine(see code below). 
I'm trying to create new property (PasswordEx) which works.
I need to add verifier to this property. Adding it using attribute. It works. Kind of..

When whole entity validated - it works and I get this field warning, etc.
What I want is INotifyDataErrorInfo to work for this property so user see wrong entry right away...

My guess is that I need to tell VerifierEngine to run verification on this property inside my setter but can't come up with syntax to do that. Or maybe I can do it some other way?

Also, how would I raise INotifyPropertyChanged event from my partial class? Is there any built-in gluing in DevForce?

[MetadataType(typeof(MEMUserMetadata))]
    public partial class User
    {
        private string passwordEx;
        [StringLengthVerifier(MaxValue = 20, MinValue = 6, IsRequired = true, ErrorMessage = "Password Required")]
        public string PasswordEx
        {
            get
            {
                return this.passwordEx;
            }
            set
            {
                this.passwordEx = value;
            }
        }
        public string PasswordAgainEx { get; set; }

    }