when the event start, hfs can create a txt file with some word, and then launch the external task
while the task is running, hfs is waiting to run the next event,
at the begining of the event, hfs read the txt and if the content is not empty it will run a break macro to stop the script event,
at the end of task, batch script must delete the txt file to inform hfs that the job has finish..
next time event is running the txt will be created and hfs launch new task