Perl is a generally excellent language for gluing applications together for the purpose of testing them. For your application, it sounds like you want an automated web client that fetches pages, stuffs them with info, and submits them. There are a number of CPAN modules that help you do just this.

I have used LWP::Simple to good effect. Here is a snippet that gets a weather web page:

   use LWP::Simple;
   my $state = shift;
   my $url_base = 'http://iwin.nws.noaa.gov/iwin/';
   $state = uc $state;
 
   # get the raw HTML page for $state
   my $url = lc($url_base . "$state/zone.html");
   my $raw_data  = get($url);
[download]

There are many other LWP modules that offer great flexibility in web programming.

-Mark