Refund of income tax- after appeal to IT tribunal

dear all,
in a particular case where
1. appeal filed against order of commissioner appeals income tax and
2. won by the assessee in tribunal
then how to get the refund of the tax already paid by the assessee for filing appeal in tribunal.
i understand assessing officer has to process the refund. but do we need to file any form or do any follow up? or refund comes automatically?
pls advise