Oops, never mind. I see that the open folder icon on the right edge of the screen (winscp 2.2) lets you type in a destination instead of selecting from a list and using /cygdrive/c there works.
i have ssh server running on windows 2000. i know, i know. in ssh server you can configure your windows drive mappings.
so in winscp or ssh client i type /d for example to access my mapping to d: