heh!some Opensuse user out here!tell me if suse uses KDM or GDM(Gnome Display manager).if it is GDM it will be lot easier(atleast for me to explain!)
KDM is K desktop manager.it is that login prompt that pops up everytime after suse loads.I dont use suse or kde,but i think suse uses KDM.In the bottom of KDM screen,there will be a menu option.search it for allowing local admin to login or something similar.enable it and try login as root.once as root in kde,u can fire yast2 manager to make ur local user account.next time onwards use as local user.
If KDM fails,then try below method.
==using terminal==
http://www.mepis.org/docs/en/index.p..._Login_for_KDM
^when suse loaded KDM(the gui login prompt),press CTRL+ALT+F1 to get a virtual console.login there as root and with ur password.when u enter password nothing is shown and cursor will not be moving.press enter after entering passwd for a "#" root prompt(administrator).there u edit as per the link i gave.
PS:If u have forgot root passwd,reset it as i think u know how to do it.else boot from livecd,mount opensuse partition,edit the files mentioned as root in a terminal.