See system.

I tried with active perl version 5.8.8 and the Win32::Symlink module got installed. But it created only directory juntion despite passing a file.

 my $oldfilename = File::Spec->catfile($oldname);
my $newfilename = File::Spec->catfile($newname);
if(-f $newfilename){ } else {
    @args = ("mklink", $newfilename, $oldfilename);
    system(@args) == 0; }
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I tried with active perl version 5.8.8 and the Win32::Symlink module got installed. But it created only directory junction despite passing a file.

To (hard) link a file on Windows, you don't need a module, just use the built-in Perl link function. For example:

link $oldfile, $newfile or die "link failed: $!";
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You should only use Win32::Symlink for directories, not files. That's because Windows junctions are for directories only; see Hard Links and Junctions and Creating Symbolic Links and Symbolic Links for details.

As for the Win32::Symlink 0.04 PPM failures you mentioned, I just tried building it from source and it failed to compile due to an incompatibility with struct REPARSE_DATA_BUFFER between Win32::Symlink and the Microsoft header files, so I just raised a ticket #71879. BTW, I was able to get it to build simply by hacking tclreadlink.c, changing REPARSE_DATA_BUFFER to MY_REPARSE_DATA_BUFFER.