You can add admin by IP address or by name.
Instead of having "ce" in the very last entry per admin, you use "d" for IP address or nothing for a name.
If your player has a dynamic IP address, then you should use name instead of IP, or some days they won't have admin.
If you're going to use their name, I recommend setting a password for them. (In "ce", the "e" means "Don't check the password". So use "ab", since "a" means "Check password" and "b" means "Check name".)
The password goes in the second set of "". In my example above, "" is blank, because I don't want admin to use passwords. You would need to set "password" or whatever for your admin.
"Anubis" "awesome" "abcdefghijklmnopqrstuvwxy" "a"
So, any user named "Anubis" who enters will have admin access if they know that the password is "awesome".
Next: tell your admin to put the following line in his userconfig.cfg file
setinfo "_pw" "awesome"
and enter the following line into your amxx.cfg file
I hope that helps! If not, let me know.