Excel formula question

mmm...could be tricky......you could try the argument IF THEN ELSE in the functions list, in conjunction with additional columns to carry out the intermediate calculations, then you can hide those columns. perhaps you could also make use of conditional formatting. any problems come back to me.....could you place a snapshot of the sheet you are designing ? just highlight the cells , copy them, and use edit "paste special", tick values when pasting into this forum.