Search for files - preg_match

I have code that saves images to a directory based on the last 5 digits of the session ID. So I have a list of images 12345-hello.jpg, 12345-goodbye.jpg, 54321-adios.png, etc.

I have a script to display the files, but there are a lot of images to load. If I only want to see the files from "12345", I would like to have the PHP display only those files.

My code to get the images:
<?php $files = glob("uploaded/*.*"); for ($i=0; $i<count($files); $i++) {$num = $files[$i];print $num."<br />";echo '"<a href="'.$num.'"><img width=500 src="'.$num.'" alt="" />'."<br /><br /></a>"; } ?>
I think I have to use PREG_MATCH, but as simple as looking for files is, it was tough for me to get to this point.

Can I get a little bump over the hill so I can search for just a string that I can input?
Thanks!

how about something like that:

$id = 12345;
$files = glob('uploads/' . $id . '-.*');
$i=0;
while(isset($files[$i])){
$mime = mime_content_type($files[$i]);
if($mime == 'image/png' || $mime == 'image/jpeg' || $mime == 'image/gif' || $mime == 'image/bmp'){

//do omething with $files[$i]
}
$i++;
}