Yes, you can. The scripts are held in a separate folder for each server. To execute a script from the game, you will need to find your server ID. This is a number which can be found by connecting to the server and typing "server,listtracks" in game. The tracks will be displayed as serverID/tracks/track.trackinfo (ex: 12/tracks/alcrest.trackinfo).
Once you find your Server ID, executing a script in game is done like this: server,exec serverID/scripts/script.mxs (ex: server,exec 12/scripts/myscript.mxs)