Create new model class in django for specific user group type
===

I have user group type "Agent" and i am creating many to may relation ship.

    class Venue(models.Model):
       title = models.CharField(max_length=25)
       created = models.DateTimeField(auto_now_add=True)
       modified = models.DateTimeField(auto_now=True)
       status = models.CharField(max_length=10, choices=status)
       users = models.ManyToManyField(User, through='VenueAgent')
    
       def __unicode__(self):
           return self.title

    class VenueAgent(models.Model):
       user = models.ForeignKey(User)
       venue = models.ForeignKey(Venue)

What i want is tha by default all users is coming in many to many users i want only specific user group. In my case which is agent. So any way to change model query set for many to many relation ship dropdown which is coming in admin panel 

   