Pass DataContext Down Through Objects in XAML

Hello guys,

I am trying to write a custom control and my problem is that the column does not not receive DataContext and therefore cannot do the binding.

My custom control looks like this:

class customControl:ItemsControl
{
  public ColumnCollection Columns { get; set; }
  ..
  ...
  .....
}

Code behind looks like this:

this.DataContext = new ViewModel()

class ViewModel 
{
  public list emplyee { get; set;}
  public string colName1 {get {return "hallo";}}
}

Column looks like this:

class Column : DependencyObject
{
 public static DependencyPoperty Name = DependencyProperty.Register(.........);
 public string Name
 {
    get { ..GetValue(...) }
    set { ..SetValue(...) }
 }
}

And my XAML looks like this:

<customControl ItemsSource={Binding employees}><customcontrol.Columns><columnCollection><column name={Binding colName1}/></columnCollection></costumControl.Columns></customControl>

Now the problem is that the column does not receive DataContext and cannot bind to the colName1 property which is in DataContext.

How do i solve this? How to pass down the DataContext to objects inside other objects inside other objects?