As far as I know, there is no explicit way to remove the title bar in a RadWindow, but it is possible to remove all available controls. Take a look at this demo
to see if it could help your project. If you add Behaviors="None" to your RadWindow it will remove all available controls that the user has, leaving you to populate the window with buttons to do anything you want.
If you need help learning how to bind these buttons to specific events inside of a RadWindow, it may benefit you to watch this RadTip on tv.telerik.com
about passing data between windows. If you remove all the available controls from the client side and leave nothing but your buttons to press, the RadWindow will surely work in this scenario.
Hopefully I could be of some help,