Long filename support in Windows Vista

Someone asked me to write them a file-handling utility for use in the
console window (CMD.EXE) in Windows Vista.  The utility is quite easy
to write in something like Borland Pascal, but I've never done so for
Windows before; is it possible to handle long file/directory names
gracefully?

(I know this is probably a FAQ but I'd like any insight as to
potential problems when trying to manipulate files in Windows from a
16-bit DOS console app)