...

my $file = param("upfile");
my $upload_dir = "Y:\\Test\\user\\videos\\";

...

    my $outfile = "$upload_dir"."";
    my ($safe_file_name) = $outfile =~ /([-\@:\/\\\w.]+)$/;
    
    if ($file =~ /swf/ || $file =~ /high/ || $file =~ /low/) {
       $outfile .= $file;

...

# [ assign some stuff gleaned from $file to $safe_file_name - mlx ]

...
    open (my $fh, '>', $safe_file_name)
      or error_msg("Can't open $safe_file_name for writing: $!");