http://support.microsoft.com/default.aspx?scid=kb;en-us;Q120716
Another option is to use a syntax that bypasses the typical reserve-word checks completely. For example, you can possibly delete any file with a command such as:
DEL \\.\driveletter:\path\filename
For example:
DEL \\.\c:\somedir\aux
If the name in the file system appears as a directory, use the following syntax.
For example, you can possibly delete any directory with a command such as:
RD \\.\<driveletter>:\<path>\<directory name>
For example:
RD \\.\c:\somedir\aux
-or-
RmDir \\.\<driveletter>:\<path>\<directory>
For example:
RmDir \\.\C:\YourFTP_ROOT's_PATH\COM1 /s /q
/s-This switch removes all directories and files in the specified directory and also the directory itself. This switch also removes a directory tree.
/q-This switch stands for Quiet mode. Do not ask if you can remove a directory tree that contains the /s switch.