Extend WP Query & return output in $post - php

Question

I'm trying to create an event site. Users at the moment can search for events within a specified radius of their chosen search location (using Google Geocode).
I have a custom DB Query, which works fine, except I want the distance of the event to display on the front end of the site also, so users know how far away each event is from them.
Here's the custom query function I have at the moment:
function location_posts_where( $where ) {
// if user has input a location
if( isset($_POST['where']) != '' ) :
// check the geo locaton of user
$geoURL = "http://freegeoip.net/json/". $_SERVER['REMOTE_ADDR'] .'';
$geo = json_decode(file_get_contents($geoURL), true);
// Geocode input value + users country code
$url = "https://maps.googleapis.com/maps/api/geocode/json?address=".urlencode($_POST['where'])."+".$geo[country_code]."&sensor=false";
$location = json_decode(file_get_contents($url), true);
// store lat and long of searched location
$Slat = $location[results][0][geometry][location][lat];
$Slng = $location[results][0][geometry][location][lng];
// if use hasn't unput a location
else :
// get location of user
$url = "http://freegeoip.net/json/". $_SERVER['REMOTE_ADDR'] .'';
$geo = json_decode(file_get_contents($url), true);
// store lat and long of user location
$Slat = $geo[latitude];
$Slng = $geo[longitude];
endif;
// Specify the co-ordinates that will form
// the centre of our search
$lat = $Slat;
$lng = $Slng;
$radius = $_POST['distance']; // (in miles)
// Append our radius calculation to the WHERE
$where .= " AND wp_posts.ID IN (SELECT post_id FROM lat_lng_post WHERE
( 3959 * acos( cos( radians(" . $lat . ") )
* cos( radians( lat ) )
* cos( radians( lng )
- radians(" . $lng . ") )
+ sin( radians(" . $lat . ") )
* sin( radians( lat ) ) ) ) <= " . $radius . ")";
// Return the updated WHERE part of the query
return $where;
}
This code works fine, however, I've used the wp_geo_posts plugin before, and that lets you output onto the screen the distance each event is from the users location using <?php echo $post->distance; ?>
With this code, there is no 'distance' output to the $post variable. Is there a way of getting this to output to $post so it can be displayed on the front end?