Hello Cindy,    
       You can do the rounding in a 'Basic Match Calculation'.  (There is another forum post on it here).  It would be setup by retrieving the value you want to round, adding 0 and selecting a rounding option.
     For commas in numbers, there isn't anything on the screens or actions that can do insertions of commas in decimals/numbers.  You can do it in the actual report designer or it can be done with the SQL override in a grid.  

I hope this helps,
Greg