how to configure httpd proxy with authentication

how to configure httpd proxy with authentication

vi gen.php

<?php
echo base64_encode("user:password");
?>

php gen.php
dXNlcjpwYXNzd29yZA==

RewriteEngine On
RewriteRule ^/orin/(.*)$    http://target.lb.com/$1   [NC,L,P]
<LocationMatch "^/orin/(.*)$">
    #AddDefaultCharset GBK
    RequestHeader set Authorization "dXNlcjpwYXNzd29yZA=="
    ProxyPass http://target.lb.com/$1
</LocationMatch>

via:httpd.apache.org

mod_headers
rewrite flags
mod_proxy.html