I can not tell you how to use unsafedisc, but what I do know is that many people have tried to copy 'The Sims' and it has been discussed many times on this forum.
As a suggestion (though it does not answer your question) you might use the search and see what suggestions are given to make a working backup copy of this, or the program mentioned in this article might be of help to you:
http://www.cdfreaks.com/news2.php3?ID=2392]CDbeta beats Macrovisions SafeDisc Update
or perhaps this one:
Beat SafeDisc with Insektors, now also for Windows 9x
What I could find using the search function are the following links, perhaps this helps :
But this may not be the complete answer to your question...maybe some else can supplement my story