After you create a unit in your script, name him _unit, and put this:
_radius = 500 + random 1500
_dir = random 360
_center = getpos player
_pos = [(_center select 0) + _radius*cos _dir, (_center select 1) + _radius* sin _dir]
_unit setpos _pos
You may want to create a whole group at _pos, so you don't end up with guys in the same group all spread out around the player.