Hello,

You will have to modify the file \CMSSiteManager\Administration\Users\User_List.aspx.cs togeter with the User_List.xml file.
A similar problem is described in the following Knowledge Base article.

FYI: If you want to edit the CMS Desk/CMS Site manager, you can find out what files are displaying the given content with the Firefox browser. "Right click on the given frame -> This Frame -> View frame info" - there is the path of the file, which contains the displayed page.

Best regards,
Boris Pocatko