RadEditor is an HTML / XHTML editor and it does not offer direct export to MS Word because it is not offer by the browser itself. My suggestion is to search in Google for some third party HTML2DOC converter that will convert the generated by RadEditor HTML content to DOC formatting and allow you to save the content in MS Word DOC file. You can find the following link useful: http://www.w3.org/Tools/html2things.html.
The following KB article shows how to export the HTML content to PDF using a third party tool: Converting RadEditor HTML to PDF format. You can use it as a base to implement your scenario with a third party control
the Telerik team