You can set up httrack in "catch URL" mode. As I understand it, you fill in the
form and httrack intercepts the form submission in order to download the page
that is displayed afterwards. 

The user guide is a bit cryptic about this. Here's what it says:

<quote>

 The catchurl option is a small application designed to catch difficult pages,
like sites protected via formulas. [I think he means forms -Ben]

You can see at <http://httrack.free.fr/HelpHtml/addurl.html> [This URL doesn't
work -Ben] a Windows description of this application. The purpose is to create
a temporary proxy, that will catch the user request to a page, and then store
this request to continue the mirror. For example,

1. browse www.foo.com/bar/ until you have a page with a form
2. fill this form to enter the site BUT do not click "submit"
3. start the --catchurl application
4. change your browser proxy settings according to the --catchurl application
5. click on "submit" on your browser
6. HTTrack has now captured this click and has stored it
7. restore your proxy settings
8. (click back in your browser)

</quote>

So I think this should work for doing a couple of example searches, if that's
what you wanted.