In one way of another you just need to get the list of agents into a multiline context element (which needs to be of course correct data type). Rick already gave you some good alternatives. You might also need to set the agents into a "correct" format (you need the prefix 'US' in front of the user ID).
>I have another container which has the list if actual agents ie user IDs for each context
I suppose you should do the needed corrections to this part. Let the functionality that gets these actual agents return the data in the correct format (add another export parameter or whatever).
Regards,
Karri