Action for exporting every group items under first level of parent layer named icons. Tested on Adobe Illustrator CS5

export_groups_to_png.js

// reference http://graphicdesign.stackexchange.com/a/26044/18833

function exportFileToPNG(dest, artBoardIndex)
{
    var exportOptions = new ExportOptionsPNG24(); // or ExportOptionsPNG24
    var type = ExportType.PNG24; // or ExportType.PNG24
    var file = new File(dest + ".png");

    exportOptions.artBoardClipping = true;
    exportOptions.antiAliasing = true;
    exportOptions.transparency = true;
    exportOptions.qualitySetting = 72;
    exportOptions.saveMultipleArtboards = false;
    exportOptions.artboardRange = "" + artBoardIndex;
    app.activeDocument.exportFile( file, type, exportOptions );
}


var docRef = app.activeDocument;

function execute(sel, folder,append)
{
    if (app.documents.length == 0)
    {
        Window.alert('No document open', 'Error');
        return;
    }

    if (sel.length == 0)
    {
        Window.alert('Nothing selected', 'Error');
        return;
    }

    var selectedStuff = sel;

    // snap position to pixels
    selectedStuff.position = [ Math.round(selectedStuff.position[0]), Math.round(selectedStuff.position[1]) ];

    // create temporary artboad for exporting

    var rect = selectedStuff.visibleBounds;

    try
    {
        docRef.artboards.add(rect);
    }
    catch(e)
    {
        Window.alert('Could not create Artboard as step of export.', 'Failure');
        return;
    }

    // determine destination

    var fileName = sel.name.toLowerCase();

    var destFolder = folder;


    if(destFolder)
    {
        try
        {
            exportFileToPNG(destFolder + "/" + fileName + append, docRef.artboards.length);
        }
        catch(e) 
        {
            Window.alert('Could not export to PNG','Error');
            return;
        }
    }

    // delete temp-artboard
    docRef.artboards.remove(docRef.artboards.length - 1);
}

var group_items = docRef.groupItems.length;
var icon_size = prompt ('Enter the value of exported icons', 64);
var file_prefix = prompt ('Do you need additional filename prefix?', '');
var folder_to_save = Folder.selectDialog('Select the folder to export to:');

for (var i = 0; i < group_items; i++) 
{
    var current_group = docRef.groupItems[i];
//    Window.alert (current_group.layer, 'Parent')
    $.writeln(icon_size);
        if (current_group.parent.name == 'icons') 
        {
            var group_height = current_group.height;
            var resize_ratio = icon_size/group_height * 100;
            current_group.resize(resize_ratio,resize_ratio);
            $.writeln(current_group.width);       
            execute(current_group,folder_to_save,file_prefix);                       
        }
}