Hi Richard Earle,
The RadEditor for MOSS uses only one configuration file in list scenarios. It is the ListToolsFile.xml, which is located in the Program Files\Common Files\Microsoft Shared\web server extensions\wpresources\RadEditorSharePoint\5.x.x.x__1f131a624888eeed\Resources
folder if you are using the AJAX version of the control and /Program Files/Common Files/Microsoft Shared/web server extensions/wpresources/RadEditorSharePoint/4.x.x.x__1f131a624888eeed/RadControls/Editor
if you are using the classic ASP.NET version. The only difference between the usage of the RadEditor in Rich Text and EnhancedRichText columns is that the EnhancedToolbar is hidden in the first scenario. So for the moment the only way of achieving the desired functionality is moving tools from the BasicToolbar to the EnhancedToolbar by modifying the ListToolsFile.xml.
All the best,
the Telerik team