No debian/ folder in .deb file

After your answerers on this thread: http://lists.debian.org/debian-mentors/2005/05/msg00381.html I tried to edit the tasksel .deb file (just for my own testing purpose atm.) And I extracted the .deb file to a folder using the dpkg -x command. Edited some of the files, and thought I could just

Modification on the installer: "Debian software selection"

Am a bit unsure whether this is the correct mailing list, but I ask anyway: Under the installation of Debian Sarge you get the option to select packages to install. There you are given these options: [ ] Desktop environment [ ] Web server [ ] Print server [ ] DNS server [ ] File server [ ] Mail