Virtualbox mounting a Windows host directory under Linux client

C_DRIVE /C_DRIVE vboxsf uid=acizmeli 0 0


or


Documents /home/me/Host vboxsf uid=1000,gid=1000,nodev,noexec,nosuid,auto,rw 0 0

(http://ericgazoni.wordpress.com/2011/03/25/mounting-virtualbox-osx-share-on-ubuntu-guest/)