Seq with custom fields

[Stefan_Salewski]

I think I have still not really learned that. I think I may write something like
    
    
    type
      ExtSeq = object
        s: seq[int]
        timestamp: string
    
    var
       es: ExtSeq
       # init
      
      es.s.add(7)
      echo es.s[0]
      echo es.timestamp
    

But I would like to just write
    
    
    es.add(7)
    echo es[0]
    

Of course I have ideas how to do it. I may define customs procs or maybe 
templates. But I am not sure what is the best solution or where I can find an 
example...