[Plugin WP Geo Posts]

Hi,
Im developing a new pluging and I need help.
I made a Geo Positional aplication outside Worpress and now Im trying to conect it to WordPress.
My aplication consists on Maps por GPS devices and I want to add some WP post with the maps helping people to guide.
My guide is the oficial wp-template-hierarchy:
wp-template-hierarchy.png
My aplication output a variable $map_id that is numeric ($map_id=1, $map_id=3, etc).
I get to echo the global variable in the index.php(WP output ) as:
<?php echo 'The MAP ID is: ' . $map_id; ?>
The problem is that I dont know how to assign a particular page to each map(always dispalys the worpress prontpage).
For example:
https://www.geoserver.com/?map=2
(wordpress is installed in root, and working)

Then I created a in wp-admin/edit.php?post_type=page a SINGULAR PAGE-STATIC PAGE that is variable post=2.

Now I need to wordpress to shows the post_id=2(at bottom) when the map_id=2 is on top.

Im trying modifing this part:

function xmlrpc_getpostcategory( $content ) {
	global $post_default_category;
	if ( preg_match( '/<category>(.+?)<\/category>/is', $content, $matchcat ) ) {
		$post_category = trim( $matchcat[1], ',' );
		$post_category = explode( ',', $post_category );
	} else {
		$post_category = $post_default_category;
	}
	return $post_category;
}

I tried:

} else {
		$post_category = $map_id;

No luck. Some help where to search or some advice.