Workratio-like field implementation

Is there any possibility in plugin sdk to implement entity that works the same as Workratio?
Specifically I want to be able to add this new field as a column and be able to use it in JQL queries.
It would have my own calculation logic, of course.

I know that the obvious way to do it is to make my own custom field, but I am specifically asking if
the sdk allows me to somehow add a new Workratio-like field which is kind of system field in Jira.