froogle preselected

Code for Preselected options on Xcart
/modules/Product_Options/customer_options.php (ln. 94-96)
$varsku = func_query("SELECT productcode, $sql_tbl[class_options].optionid FROM $sql_tbl[variants] JOIN $sql_tbl[variant_items] ON $sql_tbl[variants].variantid=$sql_tbl[variant_items].variantid JOIN $sql_tbl[class_options] ON $sql_tbl[class_options].optionid=$sql_tbl[variant_items].optionid WHERE $sql_tbl[variants].productid='$productid'");
$smarty->assign('varsku', $varsku);
}
/common_files/modules/Product_Options/customer_options.tpl (ln. 51-71)
After <select> and before {foreach}:
<script>
{literal}
$(document).ready(function() {
  var select = GetUrlParameter("select");
  $("#" + select).attr("selected", "");
});

function GetUrlParameter(name) {
    var value;
    $.each(window.location.search.slice(1).split("&"), function (i, kvp) {
        var values = kvp.split("=");
        if (name === values[0]) {
            value = values[1] ? values[1] : values[0];
            return false;
        }
    });
    return value;
}
{/literal}
</script>
(ln 74) within <option> element:
id="{section name=vsku loop=$varsku}{if $varsku[vsku].optionid eq $o.optionid}{$varsku[vsku].productcode}{/if}{/section}"

Include SKU in Froogle Export:
/public_html/modules/Froogle/froogle.php
(ln 349): $skufix = str_replace('.', '_', $product['productcode']);
(ln 353): $product_url = $http_location.constant('DIR_CUSTOMER').'/'.func_get_resource_url('product', $product['productid'], '', false)."?select=".$skufix;