Subforms and automation

Subforms and automation

If a user updates a field how do we create an automation etc. We have a field for returned parts and i want to get an email when that field is ticked. How please as Zoho tells me no automation on subforms. 
The Reason-

Why having waited for ever for FSM and given up. Plus realising that the case module is useless I caved in and set up and equipment module with a subform for the site visits rather than the adhoc of cases linked to a creator file.
The Good- finally a good mail merge so that site engineers can get a printout of previous visits.
The Bad- subforms look bad in CRM but the real big one, plus the automation issue?

InfoModeration update: Workflow Rules can now be triggered from subform row actions. Do check the announcement post for details on how it works. As the feature is now available, we're locking this thread. Please share any feedback or questions on the announcement post, where the discussion continues.