Adding Custom Controls in Collections Editor of a Dragable Componet in Desgin Time

[Coolrah]

Hi to all,
I am developing a Binder Manager which bind and unbind data from the webpage , i have almost completed the component with custom controls
But i m facing one problem that i want to show in the collection editor of Binder Manager component only those controls which are custom controls (means made by me). My custom controls are inherited from an Interface and I want to insert only those controls into my collection which are of my Interface type not all the controls.

this is class which i m workin on ! I need it to accept my interface only means controls of my type.

[Serializable, TypeConverter(typeof(CusControlsTypeConverter))]
public class CusControls
{
protected Control _control ;

[DefaultValue(null)]
public Control Control
{
get {
if(_control is ICustomControl)
{
return _control;
}
else
return null;
}
set { _control = value; }
}
public CusControls() {}

public CusControls(Control ctrl)
{
_control = ctrl ;
}
}

I need help to made this concrete class to take my Interface type of object tell me wat to do.