Object as Constructor Parameter to DataContext in XAML

Question

I have a XAML Windows class

<Window 
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:src="clr-namespace:ObjectReferenceSample" 
    Title="ObjectReference Sample" Height="300" Width="300">
    <Window.DataContext>
    <ObjectDataProvider ObjectType="viewModel:MyViewModel">
      <ObjectDataProvider.ConstructorParameters>
        **<!-- MyModel class instance defined in codebehind-->****
      </ObjectDataProvider.ConstructorParameters>
    </ObjectDataProvider>
    </Window.DataContext>
</Window>

Also in my code behind I have an instance of MyModel class that needs to be passed as constructor parameter to my ViewModel through ObjectDataProvider.

public partial class MyWindow: Window
{
    public MyModel model;
    public MyWindow()
    {
          model = new MyModel();  
    }
}

MyViewModel would like:

public partial class MyViewModel
{
    public MyViewModel(MyModel modelInstance)
    {

    }
}

I have some limitation of not being able to use DI like Unity. Please suggest me solution of above problem without DI concept only.