I am not quite sure I understand the exact issue. Could you please elaborate more on the subject? Could you please describe in more details what exactly you are trying to achieve?
If you want to configure RadEditor to look like HTML TextArea, please take a look at the following live demo for an example on how to achieve this:
Editor / Displaying RadEditor as a TextBox
the Telerik team
If you want to get updates on new releases, tips and tricks and sneak peeks at our product labs directly from the developers working on the RadControls for ASP.NET AJAX, subscribe to their blog feed