Hacking Wordpress Plugin "Google Calendar Events" - wordpress

Question

I'm currently working with the plugin Google Calendar Events. I'd like to add the ability for users to choose (via a select drop-down menu) which feed they're viewing and then have the calendar automatically display the selected feed. Does anyone know how to do this?
I know that you can use the shortcode to choose what feeds to display, but I'd rather not create an individual page for each feed, and then have links to them (there are 10+ feeds and one is added and deleted with regularity, so it's just not feasible to manually create a calendar for each individual feed).
I've added this code to the gce-script.js file in the plugin:
function changeFeeds(){
var values = jQuery("#gce-view-feed").val();
jQuery("#result").replaceWith(values);
}
jQuery("option").click(function(){
location.reload();
});
jQuery("select").change(changeFeeds);
changeFeeds();
...Where the id "gce-view-feed" is the select menu's id and id "result" is where I display the results. This works great, except how do I then pass that result to the plugin so that it uses it?
Feed ids are defined by a PHP variable $feed_ids. I think the best place to edit the variable is this line of code in the google-calendar-events.php file:
//Check that any feeds have been added
if ( is_array( $options ) && ! empty( $options ) ) {
extract( shortcode_atts( array(
'id' => '',
'type' => 'grid',
'title' => null,
'max' => 0,
'order' => 'asc'
), $atts ) );
$no_feeds_exist = true;
$feed_ids = array();
if ( '' != $id ) {
//Break comma delimited list of feed ids into array
$feed_ids = explode( ',', str_replace( ' ', '', $id ) );
//Check each id is an integer, if not, remove it from the array
foreach ( $feed_ids as $key => $feed_id ) {
if ( 0 == absint( $feed_id ) )
unset( $feed_ids[$key] );
}
//If at least one of the feed ids entered exists, set no_feeds_exist to false
foreach ( $feed_ids as $feed_id ) {
if ( isset($options[$feed_id] ) )
$no_feeds_exist = false;
}
} else {
foreach ( $options as $feed ) {
$feed_ids[] = $feed['id'];
}
$no_feeds_exist = false;
}
But I don't know how to pass the jQuery value to the $feed_ids variable. Is there a way to do this? And if not, is there another way to dynamically select an option and then pass it to a PHP variable?