[Godhimself]

Grim_'s code will work, But i noticed u asked for sscanf, here is a sscanf rebuild:

pawn Код:

COMMAND:stats(playerid, params[])
{
   new otherplayerid;
   if(isnull(params))
   {
       // Show player their own stats
   }
   else if(!sscanf(params, "u", otherplayerid))
   {
       // Show the 'otherplayerid' stats
   }
   else
   {
       SendClientMessage(playerid, -1, "USAGE: /stats [name/id]");
   }
   return 1;
}

Not tested. Should work.