Excel Macro

Hello,
I have 24
cells(12 historical data and 12 forecast data) row-wise and they are not in continuous order. I need a macro code that would make a transpose of these cells and arrange them in descending order, calculate the average value and then give a value between the average and maximum value arranged in the descending order, such that no more than 3 values should be higher than the calculated value. I need the same logic to be populated throughout the column. I am trying to do my part of the work. But getting stuck up with the macro part. I am not that good at macros. So, It would be great if you could help me out with this.