its well i dont know how to add semiadmni by guid using a command i do it manuel
goto your server folder (/rtcw/banimod) create a new folder called guid (/rtcw/banimod/guid) create a file there whit no exetension whit as filename your guid or the guid of some1 else
then open that file whit a text programm like notepad
then type inside that file
semiadmin1 (or an other level of semiadmin)
then save and exit that file
now goto the server and you will automaticly be logged in whit semiadmin and you should be able to use /semiadmin <command> (depending on the level)