AS3 - pass varible to class function (button to dataGrid)

I am trying to create buttons in my dataGrid in Flash. However, I am a begginer and I don't now how to make my function which generates button column take parameters which I need to use to each button. I need that every button has a specific Label and if I click on that button it copy googleURL to clipboard.

I don't know how to pass variables "buttonLabel" and "googleURL" to that function...

Here is the .fla part of code:

        googleURL = "www.someadress.com";
        buttonLabel = "someLabel";

        var btnCol:DataGridColumn = new DataGridColumn("buttonColumnTitle");

        btnCol.cellRenderer = ButtonCell;
        btnCol.editable = false;
        tabulka.addColumn(btnCol);

and here is ButtonCell class:

package 
{
import flash.desktop.Clipboard;
import fl.controls.Button;
import fl.controls.listClasses.ICellRenderer;
import fl.controls.listClasses.ListData;
import flash.events.Event;
import flash.events.MouseEvent;


public class ButtonCell extends Button implements ICellRenderer
{
    private var _listData:ListData;
    private var _data:Object;

    public var _buttonLabel:String;
    public var _googleURL:String;


    public function ButtonCell()
    {
        super();

        //_buttonLabel = buttonLabel;
        //_googleURL = googleURL;

        this.label = _buttonLabel;

        addEventListener(MouseEvent.CLICK, onButtonClick);
    }

    public function set data(d:Object):void
    {
        _data = d;
    }

    public function get data():Object
    {
        return _data;
    }

    public function get listData():ListData
    {
        return _listData;
    }

    public function set listData(value:ListData):void
    {
        _listData = value;
    }

    override public function get selected():Boolean
    {
        return _selected;
    }

    override public function set selected(value:Boolean):void
    {

    }

    public function onButtonClick(event:MouseEvent)
    {
        System.setClipboard(_googleURL);
    }
}
}

whow, this work perfectly, that was the problem. Thank you so much!! However there is one more thing I am not sure about... When I want to add more buttons it only displays the last one... I am not sure what's wrong. This is sample sript which draws 5 items but buttons - only the last one...

import ButtonCell;
import fl.controls.dataGridClasses.DataGridColumn;
import fl.controls.listClasses.CellRenderer;
import fl.controls.DataGrid;
import fl.data.DataProvider;

var googleURL:String = "www";
var buttonLabel:String = "bt";

var provide = new DataProvider;

var tabulka:DataGrid = new DataGrid();
tabulka.x = 50;
tabulka.y = 50;
addChild(tabulka);
tabulka.setSize(400, 300);
tabulka.columns = ["Parcela","Odkaz"];
tabulka.columns[0].width = 50;
tabulka.columns[1].width = 350;
tabulka.selectable = false;
tabulka.dataProvider = provide;

var btnCol:DataGridColumn = new DataGridColumn("Copy");
tabulka.addColumn(btnCol);
for (var i = 0; i<5; i++){
    provide.addItem({Parcela:"Item "+i});
    btnCol.cellRenderer = new ButtonCell(buttonLabel = "bt"+i, googleURL = "www" + i);
}