Allow Usermanager Admin GUI, disallow Routerboard WebGUI

Hi,
is there a possibility (with RouterOS possibilites only, no separate ReverseProxy and so on) to allow Web Access to Usermanager Admin GUI (http://x.x.x.x/userman) but to disallow regular Admin WebGUI? I don´t want to see the Admin GUI when going to http://x.x.x.x.
Regards
Martin