where is the setting to make konqueror save files in a certain subdirectory?

I tried to find it in its configuration Settings > Configure Konqueror
and via start up parameter: konqueror --help ...
but I couldn't find anything useful

use cases, you would like to:

1) start a live distribution off of a DVD and don't want for downloads to go into some subdirectory in "/home/user"

2) download a number of large files in a row which you would like to safe in certain subdirectory

lbrtchx