is it possible to change value of column into column_name

i have tables with these columns
file_no
amount
date
and another table
file_no
day1
day2
.
.
.
day31

what i have to do is select the day part of the date(suppose 12/18/2009 i have to select 18) and put the value of amount into another tables column of that day (suppose day18)
please suggest me how to do that
is there any procedure to overcome this problem