Complex formula to find max value of range based on multiple variable
 

Need help with a formula to find the max value of a range that is determined by a signal in column J that creates a lookback 2 values in Col F to set the range of column C where the max value is pulled from. The max value from the range is then subtracted from it's corresponding value in col I. I have attached an annotated sample that will hopefully better map out what I'm trying to do.