@CWD[d:] : Returns the current working directory of the specified disk drive in the format d:\pathname. If the current working directory is the root directory, the format is d:\. The drive letter must be followed by a colon.
If the argument is a partial filename without a drive, @CWD will expand the filename to get the drive.
Examples:
echo %@cwd[C:]
c:\Windows
echo %@cwd[%_disk:]
D:\release\version14
See also: @CWDS.