From FCKeditor Docs

RenameFolder

Renames a folder.

Sample Request

Renames the folder /My Folder/, of the resource type “Files” to “Another Name”.

connector.php?command=RenameFolder&type=Files&currentFolder=%2FMy%20Folder%2F&NewFolderName=Another%20Name

Note that “currentFolder” contains the complete path of the folder.

Sample Response

<?xml version="1.0" encoding="utf-8"?>
<Connector resourceType="Files">
 <Error number="0" />
 <CurrentFolder path="/My Folder/" url="/userfiles/files/My Folder/" acl="255" />
 <RenamedFolder newName="Another Name" newPath="/Another Name/" newUrl="/userfiles/files/Another Name/" />
</Connector>

Note that folder names may contain non ASC-II chars.