Suppose you have a fixed compound interest rate Ci (say 1%), a fixed simple interest rate Si (say 2%), and a total of N months (say 24). So, if you have a start value V (say 100 dollars), at the end of the N months you will have a total final amount FA of FA = V x (( 1 + Ci) ^ N ) x (1 + N x Si).
Is it possible to convert that expression in a sum of N expressions that depends on Ci, Si and N? My question is that, when I try to find FA using a Excel spreadsheet, row by row (I mean, using N rows, one for each month), the final result is lesser than when I use the formula above, because of the simple interest rate. But I would like to "see", month by month, how each part of the amount (value, compound interest and simple interest) increase and evolve to the final result.