You could even try to hardcode something
If you don't have a lot of admins or simply don't change them often and you have the same 2-5 admins each time you could just hardcode something on player_putinserver
check if the current map's prefix is de_ or cs_ and give them the flags u want for that map.
and if the prefixes are not met just give them all admin or strip them all off their rights checking their steam_id's.
no need to modify users.ini or anything like that.