Once your Perl CGI program has run and you're ready to display the results, you have a couple of choices. If the results are dynamic and different for every user, then the custom HTML generation will have to be part of the CGI program. If, on the other hand, the same results will be displayed to every user (a thank-you page, for example), then there's no reason to generate the HTML every time as part of the program. It makes more sense to send the user to an existing static HTML document. Your program will run faster, and server load will be less. For example:
print "Location: http://myURL/thanks.html /n/n";
This line will send the user's browser to whatever URL you specify. Don't forget the two newline characters; they're necessary.