You might also still use the normal rcon commands to do so when you're on the server yourself or use another server browser application (I forgot the name, but when only CS 1.6 was around and Steam just had started people used it frequently, it might have been HLSW or ASE) to send rcon commands to the server without playing on it and without having to modify your server.
Other than that it's easiest if you do like major suggested: use a batch script.