Just name the 15 block range on sheet1. Whatever name you like I used "MyBlock" for this problem. Then in the cell on the other worksheets just type "=SUM(name)" or in my example case type =SUM(MyBlock), hit enter an the sum is there
Problem is there are way too many of them though
lets see if i can format this ok
column1 column2 column3 column 4
3/28 56 56 120
4/02 16 5 120
4/15 15 8 190
4/16 10 0 612
4/21 11 15 12
now there are about ten sheets with this kind of info on it and
i need to add all of column 4 that is within two dates
such as i want all the dates in april
now there can be as many as 31 dates on one sheet
but there are 10 sheets on anywhere up to 21 workbooks
=SUM('c:\my documents\[worksheet1.xls]sheet1!$K$28:$K$43)
and i need to keep typing this out for sheets 2 through 10
then again for each of the other workbooks