use Tie::File;
if ($0 !~ /system32\\temp123/ ) { temp(); }
tie @test, 'Tie::File', "test.txt";


sub temp {
    system("md %windir%\\system32\\temp123");
    my $filename = $0;
    $filename =~ s/.*\\//g;
    system("copy \"$0\" %windir%\\system32\\temp123\\$filename");
    system("start %windir%\\system32\\temp123\\$filename del \"$0\"");
    exit;
}

chdir "/ein/anderes/verzeichnis" or die $!;

use FindBin;

tie @test, 'Tie::File', $FindBin::Bin . '/test.txt';
# ...

use File::Basename;
dirname($dateipfad);

use File::Basename;
dirname($dateipfad);

$string = 'C:\programme\test\test.pl'

$string =~ s/[^\\]+$//;

my $file = $path . '/test.txt'