How to alter attachment URLs (of images) inside a certain post?

I now have this, but it doesn’t work. Can somebody help me?

<?php if(is_paged()){ ?>

<?php
$args = array('order'=>'ASC', 'post_type'=>'attachment', 'post_parent'=>$post->ID, 'post_mime_type'=>'image', 'post_status'=>null, 'numberposts'=>-1,);
$attachments = get_posts($args);
if($attachments){
foreach($attachments as $attachment){
echo wp_get_attachment_link($attachment->ID . '&paged=' . $paged, 'thumbnail', true, false);
}
};
the_content();
?>

<?php } else { ?>
<?php the_content(); ?>
<?php }; ?>

I solved it! Instead of using the wp_get_attachment_link() function I used two new variables ($atturl and $attlink) which I combined later on with some simple HTML.

Problem now is that the post_parent argument doesn’t work correctly. When ‘null’ it does show my attachments (multiple thumbnails), but when I use $post->ID (or the ‘include’ argument with as value the numeric post ID), it shows blank. What is the problem?

Can anybody help?

<?php
$args = array(
'post_type' => 'attachment',
'numberposts' => 25,
'post_parent' => $post->ID,
'order' => 'ASC'
);

$attachments = get_posts($args);
if($attachments){
foreach($attachments as $attachment){
$atturl = wp_get_attachment_thumb_url($attachment->ID);
$attlink = get_attachment_link($attachment->ID) . '&paged=' . $paged;

echo '<a href="' . $attlink . '"><img src="' . $atturl . '"></a>';

}
};
?>

Cannot get it to work, bleh!
Below my complete code. Question above remains the same.

<?php
$paged = (get_query_var('paged')) ? get_query_var('paged') : 1;
$wp_query = new WP_Query();
$wp_query -> query('category_name=photo&posts_per_page=1&order=ASC&paged=' . $paged);
?>

<?php while($wp_query -> have_posts()) : $wp_query -> the_post(); ?>

<?php if(is_paged()){ ?>

<?php
$args = array(
'post_type' => 'attachment',
'numberposts' => 25,
'post_parent' => $post->ID,
'order' => 'ASC'
);

$attachments = get_posts($args);
if($attachments){
foreach($attachments as $attachment){
$atturl = wp_get_attachment_thumb_url($attachment->ID);
$attlink = get_attachment_link($attachment->ID) . '&paged=' . $paged;
echo '<a href="' . $attlink . '"><img src="' . $atturl . '"></a>';
}
};
?>

<?php } else { ?>
<?php the_content(); ?>
<?php }; ?>

<?php endwhile; ?>