SugarCRM customisation

We need some email notifcation additions to the ACTIVITIES - 'tasks' module. Email all stakeholders, not just the user the task was assigned to. When somebody creates a task, the 'User" of the account is notified, the "User" who assigned the task is also notified they created a task, and the 'User" the task was assigned gets an email notification stating a task has been assigned. So three (3) notification emails are sent. When the task is completed the 'User" of the account is notified, the "User" who assigned the task, as well as the 'User" the task was assigned to stating the task has been closed/completed. So three (3) notification emails are sent. When/if the task is re-opened, the 'User" of the account is notified, the "User" who assigned the task is also notified, and the 'User" the task was assigned to stating the task has been re-opened. So three (3) notification emails are sent.