There is no real good way yet. (bugs have been filed about no wine specific choice in Dash > Files and Folders
If you open Dash > click on Files & Folders icon you should be able to search "drive" & have drive_c show up in the results.
To do so you need to do 2 things. First - no folder will show unless you've opened a file directly in that folder.
By default drive_c has no files in it, so go to drive_c, create an empty file & open it in a text editor.
2nd - when searching in 'Find files' (Files & Folders), you need to "Filter results" > Type > Folders
If you do both of the above then drive_c should show after dr in the search box.
Not really much of a solution...
An alternate -
Go to drive_c, create a very uniquely named text file & open it in a text editor.
Then you could simply open Dash > find files, search it & D&D the file from the dash on to the home folder icon in unity launcher. A nautilus window will open @ drive_c
To enable this to work correctly in 11.10 you need the Exec= line in nautilus-home.desktop to end in %U as in
Exec=nautilus %U