Spread analysis worksheet

Hello, my name is Walter. I am a 20 year old intern at a hedge fund, and I have been asked to create a formula to analyze the spread(risk) of a large number of indexes. My analysis has a few requirements.

1. That I make my data fully compatible with interchangeable data that can be downloaded and swapped into the workbook ( I have done this), so that when the data is update or new indices are added the calculations of stdev, mean, current value, etc... will all update automatically. Here is the data I want my calculations to correspond with.

\1

2. That is use conditional formatting on the current value of the index to determine how many standard deviations it is within (I have done this). Basically what this does is allow my boss to see when an index is particularly risky, therefore yielding a high return.

\1

3. The third requirement is a bit tricky though, and I am completely stumped, because I am a total noobie with array formulas.
At the top corner of my calculation worksheet I have two dates, the 'initial date' and the 'final date'. My boss wants to be able to change these dates and have the data calculated below correspond to the date changes. Here are the dates (circled in red) I want to be able to change, and then have the data below reflect the changes in date.

\1

Any suggestions would be a great help, as I am comletely lost on how to do this... I thank you all for your time and attention.

Sincerely,
Walter