xampp: FTP passwords?

This is probably the wrong group for this question, but I don't know
where else to look. The xampp forum seems to be in German.

I've set up xampp with Apache, but I'm wondering how to go about
setting the configuration for the FileZilla FTP Server. By that I mean
how do I tell it which directory on my machine to look in when I log in
to a particular site through FTP? Also, how do I change a site's
username and password for FTP? Are these specific to FileZilla, or is
it done in a config file like "config.inc.php"?

Currently, I can only FTP to my sites using the default user/pass
"newuser/wampp", and that takes me to the htdocs root directory instead
of to the appropiate subfolder.

Thanks for any help.
--ZenBug