Please, note that RadEditor is DHTML web editor, but not an ActiveX control as RichTextBox.
If you want to have non editable areas in RadEditor please, look at the following help article: Editable and Non-editable Areas
If you experience any problems, implement your scenario using an editable DIV element ( <div contenteditable="true" style="1px solid red;width:300px;height:300px;">sample content</div> ) as the editor. If you are able to implement a fully functional solution, we will help you integrate it into the editor and use the editor content area as a source area.
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