how to open a folder

not understood.

What means: just want to open a folder ??

For what purposes?

to copy a file out of it.

Do you want to open it in python or do you want sikuli to open it?

In Python you can open a file with something like

open("C:\\Program Files\\Microsoft\\Microsoft Access 2010 Interactive Guide\\ClientBin\\xyz","r")

or if you want to copy a file

shutil("C:\\Program Files\\Microsoft\\Microsoft Access 2010 Interactive Guide\\ClientBin\\xyz", "C:\\new\\location\xyz")

If you want Sikuli to open it on the desktop, I can't see the problem, doubleclicks and some images should do.

I thought I might be able to prevent doing 7 doubleClick steps with Sikuli but apparently I can't.
Thanks!

You should defenitely do file copying like RaiMan explains it, it is a lot faster and safer than doing it with Sikuli.

*** rewrite of hidden comment #5, which contains errors

This can be done with Python functions:

import os
import shutil
inFile = os.path.join(some_path, some_filename)
outFile = os.path.join(some_other_path, some_filename)
shutil.copy(inFile, outFile)

the ..._path variables have to be set to an absolute path and the path's must exist.