I'm running a workflow rule to update a particular field on one of my modules. The field, ideally, would be read-only (user can read the value that the workflow rule sets the field to, but cannot change the value). 

Is the workflow rule able to set the value of that field even though the field is read-only, or do I have to make it editable? Any other way to accomplish a similar end goal?

This script is a workaround in lieu of Zoho having formula fields that could display a value from a parent (related) record in a field.

Regards,

Darryl