Only 1 redirect possible?

Here is what there is in my .htaccess:

ErrorDocument 404 /auction/index.php
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]

# add a trailing slash to /wp-admin
RewriteRule ^([_0-9a-zA-Z-]+/)?wp-admin$ $1wp-admin/ [R=301,L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-(content|admin|includes).*) $2 [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(.*\.php)$ $2 [L]
RewriteRule . index.php [L]
Redirect 301 /auction/404.php http://boostypress.com/auction
Redirect 301 /veiling/404.php http://boostypress.com/nl
Redirect 301 /nl/404.php http://boostypress.com/nl

Only ‘Redirect 301 /auction/404.php http://boostypress.com/auction’ works. I tried to add resembling lines for additional redirects as the first line but I don’t get the 2 other at work.

I set these redirects in my hosting account and in the headers of the 404.php:
<?php wp_redirect( "http://boostypress.com/nl", 301 );?> and
<?php wp_redirect( "http://boostypress.com/auction", 301 );?> but only the second works.

Please, how do I get more than one 301 redirect at work?

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