prior for site in apt-get

["abdelkader belahcene" <abelahcene@gmail.com>]

HI,
I have a local repository ( usint apt-get procedure0 , and I defined a
remote one ( official debian), when I install a package I want to use
first my local ( if the package exists) if not I takes it from the
remote.

How and where to precise it,

thanks a lot
best regards
bela