How can I add buttons to Toolbar on Modal Window?

Hello Alex,

I am not sure if I correctly understand the desired scenario. Could you please be more specific as well as clarify the following:
    - "needs to be able to Clone or Add & Clone lots and lots of records from within the modal Kendo window". How are these records visualized? Do you use a Kendo UI Grid inside the RadWindow?
   - "adding custom actions" - By a custom action you mean a server-side ASP.NET MVC Action method or the action or you mean Kendo UI Window actions like minimize, maximize, etc.?

If you want to submit the content of the window you should ensure to wrap the content inside a form element. More information on the matter is available here - http://docs.telerik.com/kendo-ui/aspnet-mvc/helpers/window/overview#htmlbeginforms-inside-windows

It will be useful if you can send us a fully runnable sample as well as describe the actual and the expected behavior of the window.

Regards,
Danail Vasilev
Telerik by Progress