Hi Lukasz Zarczynski,
Thank you for contacting us.
The RadEditor for Sharepoint(MOSS) is included in your RadControls for ASP.NET License. It is available for download from your Client.net account-> My Licenses->My Purchases -> RadControls for ASP.NET-> RadEditor-> Downloads -> Full Featured Editor for MOSS. For your reference please see the attached screenshot.
Let me know of you have any questions
the Telerik team