Hi i solved you problem by always calculation for example todays date -364. the outcome of this would bring you Wedensday in week 28 (I think thats the week no at the momente ;-))
I hope this hepls you a little bit because for me right now is not exactly clear what you are trying to achieve.
Thanks alot MT . This helped little . This is what i got :
The Values shown corresponds to year 2011, However , I need another expression which would displays the values in year 2010. E.g. My value on 1/1/2011 is 553 and value is 1/2/2010 .. table should display that value as well .
1/2/2010 1/1/2011 Sat Actual CY Actual PY 553 551