a) You could use 'pre-script' functionality (refer to the admin guide)
Create a script to check and detect the occurrence of the 'event'. Schedule the backup to run every hour. The backup will only effectively run if the condition attached to the pre-script allows it. The backup won't run right when the 'event' completes but will run within an hour after the event occurred.
b) Use MCCLI functionality (refer to the MCCLI guide)
The 'event' would need to be able to trigger a script which then launches the backup via MCCLI