decline analysis

you will have to write a code in python capable of perform a task over a microsoft excel spreadsheet, which is given attached. Basicaly you have three tables, table 1 contains expected result, while table 2 contains equations to be applied, and table 3 conditions that modify results calculated in table 2. on table two you will find two equations to determine the curves. which equation to use depends upon value of b. If b = 0, then equation is shown in cell u5. If 0<b<=1 then the equation should be found in cell r4. table 3 will modify values calculated by equations, following these rules: if value on table 3 is 1, nothing is modified. If value is 4, then value is modified to zero, and if value is 3, value is modified by a constant equals to the cell above. Take a look at column T to better understand as well as lines 4 and 5.