Queries :: Random Record Pull

I have two tables, one table Data has member(SUBSCRIBER_ID) data including service rep(UserName). Another table ServCoord has data including service rep and their manager. What I am trying to do is pull 5 random accounts per service rep. I can pull 5 random accounts, but not per service rep. I have currently 77 service reps. Is there any way I can pull 5 random accounts per service rep? Here is my starting point so far.

SELECT TOP 385 [Data].SUBSCRIBER_ID, Rnd(1) AS Expr1, [Data].UserName, Rnd(Len([UserName])) AS Expr2
FROM ServCoord INNER JOIN [Data] ON ServCoord.ServCoord = [Data].UserName
GROUP BY [Data].SUBSCRIBER_ID, Rnd(1), [Data].UserName, Rnd(Len([UserName])), [Data].SUBSCRIBER_ID, [Data].UserName
HAVING ((([Data].UserName)<>"NULL"))
ORDER BY [Data].UserName, [Data].SUBSCRIBER_ID;