How to modify the Result set of Calculation View before output

Dear All,

we have a ANA view, it gives the result like below;

------------------------------------------------------

document  item  material  Amount  Price

1                1       MM01     10         10.22

2                1       MM02     12         15.00

We need to get material price and update field price above by

some logic(cannot use join),

Finally, we'd like to display result like below

------------------------------------------------------

document  item  material  Amount  Price

1                1       MM01    10           21.45

2                1       MM02    12           13.44

Could anybody tell how to do this in cal view?

Regards,

Shidong