That leaves getting a Perl handle from the Win32API::File object:

use strict;
use warnings;

use Encode         qw( encode );
use Symbol         qw( gensym );
use Win32API::File qw(
   CreateFileW 
   OsFHandleOpen
   CREATE_ALWAYS
   GENERIC_WRITE
);

my $qfn = chr(0x2660);  # Whatever

my $win32f = CreateFileW(
   encode('UCS-2le', $qfn),
   GENERIC_WRITE,             # For writing
   0,                         # Not shared
   [],                        # Security attributes
   CREATE_ALWAYS,             # Create and replace
   0,                         # Special flags
   [],                        # Permission template
)
   or die("CreateFile: $^E\n");

OsFHandleOpen( my $fh = gensym(), $win32f, 'w' )
   or die("OsFHandleOpen: $^E\n");

print $fh "Foo!\n";
[download]

ikegami,

Back to the original question: Your solution shows how to save a file when you *know* the encoding for one character.

I don't know what users will upload. So I need to convert the file names on the fly. In fact, they might not even use Chinese. They might use Korean, Japanese or just English. I need a solution that would be language independent.

Years ago, I remember seeing some Perl program that would use the bytes pragma to do the conversion. Would that help?

Thanks ikegami.

This new problem really has nothing to do with your original question, and should get a new thread rather than being directed at me.

Try clearing up the problem definition while you're at it. I think you want to determine the encoding of the names of files uploaded via HTTP POST requests, but that involved guess work.