This one is for the list of Forums:
    Search For:
        (tabid/\d+/view/topics/forumid/\d+/)Default.aspx">([^<]+)</a>
    
    Replace With:
        $1DNN-$2.aspx">$2</a>
    
These are for specific Forums by ID    
    SearchFor:
        DotNetNuke/Support(/tabid/\d+/forumid/12/postid/\d+/view/topic/Default.aspx)
      
    Replace With:
        DNN-Tips-And-Tricks$1
        
    Search For:
        DotNetNuke/Support(/tabid/\d+/forumid/16/postid/\d+/view/topic/Default.aspx)
        
    Replace With:
        DotNetNuke-Tutorials$1