How to give dynamic values in Gettwitter processor 'terms to filter on' parameter during run time.

[#1]

My requirement is to extract a person's tweet info, on which I need to get the tweets of the followers too in run time. For this, I am planning to create a config file, that may have list of main user, its followers etc. This file I need to provide it under gettwitter, so that i could get the followers tweets too. Any help on how can I acheive this.