Under "Add Condition to Transistion" I would like to duplicate the "Only Assignee Condition" but with a different field name (e.g Project Manager, Evaluator, Verifier, etc.). What steps do I need to take?

a) Do I need to create a seperate plugin?

b) Can I just modify an existing plugin? How?

c) Do I need to just copy the code for "Only Assignee Condition" within the system-workflow-plugin.xml
(in ~/atlassian-jira/WEB-INF/classes/)?