How to Copy Custom field value to System field ?

Question

I have a CustomField as selectList and SystemField is Label . When we select a value in the selectList and submit. we want the selectedValue to be copied as Label on the issue.  How can we acheive this ?

Note: I tried postfunction Copyvalue from field but it is not working. Is there anyway i could resolve this.

Zul NS [Atlassian] · Accepted Answer

If you are looking for a plugin, JIRA Misc Workflow Extensions can do this on post-function