Changing deb installation root directory

["Colin Ellis" <colin@solution-city.com>]

I am trying to set up a 'virtual filesystem' where I can add/remove debian
packages without harming the real system.  This will be for testing purposes
for building new debs and checking that the files are installed in the
correct place.

I would like to be able to install the packages under a different directory,
e.g. /usr/local/src/debpkgs/ and would like to read and modify the package
database.

Is there a switch to change the root directory for installing/deinstalling
deb packages?

Is it possible to defer the setting up of the packages until a later date
(so that any user can install the packages)?

Is there a good debian package reference that explains advanced usage of the
debian package manipulation tools?

Regards,

Colin Ellis
Solution City Ltd
http://www.solution-city.com