code checking write-permissions directories win2k/xp

greetings!

i am perplexing check office write-permissions within windows mfc/atl way controlling c++. initial speculation c-standard _access function, e.g.:

if (_access("c:\mydir", 2) == -1)
   // office writable.

but apparently windows 2000 xp, _access can't establish office permissions. (i.e. confidence add-on properties dialog right-click office explorer) so, there an glorious proceed establish directory's write-permissions windows 2000/xp controlling any windows c++ libraries? so, how?

thanks

evan