Is it possible to update a custom subject picklist via Salesforce workflow rule?

Hi Manpreet,

Create a new Custom Picklist Field for Events and/or Tasks

1. From Setup, go to Customize > Activities > Activity Custom Fields.
2. Create a Custom Picklist called “Event Subject".
3. Populate the picklist with the preset phrases you want to use for the "Subject" field.

Note: No need to add this new field to existing Page Layouts.

Add the new Custom Picklist to the Publisher Action Layout

1. From Setup, go to Create > Global Actions > Global Actions.
2. Next to the “New Event” action, click Layout.
3. Remove the existing "Subject" field from the layout and replace it with your new “Event Subject” field.
4. Once this is saved you can check the "Publisher Action" button on your device and see your new picklist.
   Build a Workflow Rule

To copy the value from our Custom Picklist to the built-in Subject field:

• From Setup, go to Create > Workflow & Approvals > Workflow Rules.
• Create a new Rule:

Step 1: Object = Event
Step 2: Rule Name = Copy Event Subject
Evaluate the rule when a record is = Created
Run this rule if the following = criteria are met
Field = Event: Subject
Operator = equals
Value = (leave this area blank)
Step 3: Add Workflow Action “New Field Update”
Name = CopyEventSubject
Field to Update = Standard field: Subject
Use a formula to set the new value
Formula Value (Text) = TEXT ( Event_Subject__c )
Note: the value inside the parentheses is the API name of your custom picklist
Save

• Click Activate at the top of the Workflow Rule detail page.