First: dpkg has no special knowledge about this directory. It's just a
random directory the APT family of programs use to store downloads, which
will instruct dpkg to install this or that exact deb-file from there, so
dpkg can't help you here.
Thank you so much. It is wonderful when I receipt your reply. Before, I doubt my mail will be replied. Thank you.
In Indonesia, we use oftenly apt-web at http://repo.ugm.ac.id/apt-web/index.php. We can ask 1 application name, and its system will give us all links to download (the app plus complete dependencies). After downloading (say, shutter), you get a folder contains all DEB needed for installing shutter. Take that folder home. So, we do just sudo dpkg -i *.deb inside that folder. You can try that. Why does Fajran create apt-web? Because Indonesian people has limited internet bandwidth until today. So, for many Indonesian people, apt-web is strongly useful and almost perfect way.
So, come from apt-web and sudo dpkg -i *.deb, I think I can use some command (either dpkg or apt-cache or sed or else), to install an application from a folder, named /var/cache/apt/archives. If I do sudo dpkg -i *.deb inside there, all DEB will be installed. And all applications there are automatically installed. Nah, now I want the similiar command to track and take only 1 application (not all) from /var/cache/apt/archives/. If dpkg can track dependencies of an application in 1 folder, why not it can track same application in 1 folder but between so many others DEB? I think theoritically it can be, and it is possible, but I don't know the command.
It is the clearest I can explain unto you. I am sorry for bad English in my limitation of language. Thank you so much, Developers.