slecting averages from a changing table
 

i have a spread sheet set up to colect data on a daily basis from Jan 1 to
dec 31. i want to be able to have a month by month average of slect coloms
show up off to the side for quick access. colum a converts the date from
colum C in to the numerical value ( jan = 1 ect), Colum B show what week of
the year the date falls in to (jan 1 = week 1 of the year),colum C has the
dates in it, data is input in colums D to M. so i want to be able to take the
data in coulm H and M and be able to average everything that has a jan date
in to cell N4, feb in to cell N5 ect..can it be done?