you can fetch the job's result from the database by jobID, and set an output value on the workflow model itself. is this what you're hoping to accomplish?
*Edit - found an old project where I grabbed the result code from the eXpress db.
select s.[exit_code]
from [event_schedule] s, [event] e
join [event] e on e.[event_id] = s.[event_id]
where e.[event_id] = @job_id
and s.[computer_id] = @computer_id
the results of this query can be used as the output of the workflow model.