I thought I had, click the link I gave for the google search on "tor.exe" in site forum.avast.com.
When those results are displayed, bookmark the results, in the normal way you would bookmark any web page. I have a little folder for Google on my toolbar I dragged the icon to the left of the firefox address bar into it, it is now saved in that folder.
Should I want to do a search of the forums using google:
1. I would just click that bookmark and those results are displayed.
2. I then change the search string that is in the google results window, adding the new search and leaving the site:forum.avast.com part.
3. Now when you click enter it completes the search on your new search string within the forums and you don't have to type in or remember the site:forum.avast.com part.