Is this possible?

[Mikenell]

I read a while ago about a debian command to make an iso image from the way its currently setup, so, if I wanted to format, would I be able to make the iso with that command (I cant remember what it is tho) then format, reinstall debian from my 2.2 cd's, then add the cd I made to apt sources list and then apt-get dist-upgrade which will put my system back to the way it was before I formated (package version wise), obviously my config would be lost but I could get things setup right by running config programs etc.
Is it possible, and if so, whats the command?
Thanks
Mikenell