if you know the path of your files, create a .htaccess file like:
[code=.htaccess]
AuthUserFile /var/www/path/to/.htpasswd
AuthName "Members Only"
AuthType Basic
require valid-user
[/code]
Then, use
http://www.flash.net/cgi-bin/pw.pl and type in the username/password that you want -- it'll create a line like:
[code=.htpasswd]
test:kHoJCaJBSVU9g
[/code]
Upload that as .htpasswd
At this point, you should be able to log in with the user/password -- if not, you probably have the path wrong. Upload this:
[code=cwd.php]
<?php
echo getcwd();
?>
[/code]
And then call:
http://yourdomain.com/cwd.php
and use that as the path in the .htaccess file.