WPF "Insert" control per binding

I have a UserControl without Content, because the control which should be shown inside of the UserControl is created at runtime. I would like to solve this like follows, but don't know how to implement it:

1. Create a Control-variable in the ViewModel
2. Set it at runtime when the content is created
3. Bind a content pro开发者_运维百科perty (inside the UserControl) to that variable

The problem is, that I don't know how to bind to the control-variable.

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Why just not to use ContentControl instead of UserControl and provide Content in runtime by introducing a DataTemplateSelector which able to provide right DataTemplate in runtime? You can encapsulate your Content-area controls in DataTemplates and select appropriate one in runtime.