You can create a simple PHP web page that accept UserId and print password. You can use Wamp server on windows to run PHP site on local machine.
WHile setting HHTP transformation HTTP Properties specify Base Url as the page address where you are submitting the form (i.e web page address you specified in action part of html form tag. In this case /httptrans/submit.php)
Note: Port name in HTTP transformation shall be same as of what is mentioned in form elements.
Below is sample code.
<form action=httptrans/submit.php' method='post'>
User: <input type=text name='userid' /><br/>
<input type="submit" value="submit" />
/* your database operation */
echo "User added"; // this output is sent to http transformation as response
This should work.