MATLAB: Cumulative sum function of daily rainfall

Question

I have a large daily rainfall data and require to create a new series with rainfall of 1, 2 , 3 and 4 day will be same as observed, then day 5 rainfall will be sum of 1, 2,3, 4 and 5 day rainfall. 6 day rainfall will be sum of rainfall of 2, 3, 4, 5 and 6 day rainfall. Repeat this function for 50 years daily rainfall data. Could any body suggest me matlab script for this kind of analysis? data file will be like this

date      rainfall   Cumulative rainfall
1/1/1950  10                10
1/2/1950  0                  0
1/3/1950  0                  0
1/4/1950  0                  0
1/5/1950  15                 25
1/6/1950   5                 20
1/7/1950   10                35
1/8/1950   7                 42
.........

Answer 1

conv() the rainfall data with one(1,5)