extracting a zip archive via elisp (with no external executables)

[Saulius Menkevičius]

Hello,

I am looking for a package (or integrated functionality in Emacs) 
which I could use to extract a .zip file to a specified folder. So far
I have not found any functionality that can be used to do this
programatically.

There is arc-mode.el but it references existing binaries that should 
be available on the system (unzip, 7zip, etc.)

Those executables are (usually) present on UNIX systems on $PATH, 
but on Windows I am out of luck, apparently.

What I am trying to achieve is:
 - download a .zip file (via url-copy-file)
 - extract it to ~/.emacs.d/.cache/<package>/ subdir

Any hints?

Thanks,
-Saulius Menkevicius