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(0x263a);  # 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";