That's the version of perl and the platform, but nothing about your code. Assuming this is CGI based something like the following before serving your file:

print $q->header(
        -type => "application/x-download",
        -'Content-Disposition' => 'attachment; filename="FileNameGoesH
+ere.csv"'
);
[download]

If you aren't using CGI, post some code to get better answers :)