I apologize for the delayed response. At this point it is most likely no longer of benefit to you; however, hopefully it is helpful for someone else.
In order to do this you will want to add a "Hyperlink / Redirect" item on the "Completion Events" page of your survey. When creating the item you will want to do the following. In the "Link/Redirect URL" field enter the base URL and the name of the query string parameter to be included. Next use Checkbox's pipe feature to include the response data. In my example I am going to demonstrate a single pipe but you can add as many as you would like. At this point your URL should look something like:
http://www.prezzatech.com?response1=
To add a pipe click on the pipe icon next to the URL field. After doing so the "Select Pipe" panel will be displayed. Select "Item Data" from the first drop down menu and the question you are interested in from the second, context sensitive, drop down menu. Once you have selected the source of the pipe you will need to click on the green "+" icon to add the pipe. After adding the pipe your url should look something like:
http://www.prezzatech.com?response1=@@1234
Note that 1234 is the question id.
For additional information on piping please see the "Piping basics" video in our training section.
http://www.prezzatech.com/training/