[silin]

а по-простому если:

var myDP_array:Array = new Array({name:"Sonya"}, {name:"Sundy"},{name:"Sunny"},{name:"Lolly"},{name :"Kandy"});
//my_dg.dataProvider = myDP_array;
var sorted_array:Array = [];
for (var i:Number = 0; i < myDP_array.length; i++) 
{
	if (String(myDP_array[i].name).substr(0, 3) == "Sun")
	{
		sorted_array.push(myDP_array[i]);
	}
}
my_dg.dataProvider = sorted_array;