How can I get the NTFS fileowner?

Hi everyone... I just wrote my first PHP app (a simple directory searching page for an FTP server) - it works great, but I'd like to display the uploader's name next to each file. Unfortunately, it seems that the fileowner() function always returns zero on Windows (?), and even if that worked I couldn't resolve it to a username because it appears that posix_getpwuid() and the rest of the Posix extensions are not available for Windows(?). I know how to get the NTFS fileowner in 'C' - if there's no other solution, I guess I could write my own PHP extension - not exactly sure how difficult that is, though - any ideas on any of this? TIA.. - Steve