I have a spreadsheet that has data for each month. At the bottom of each
month is a summary of the data in four categories. What I need to do is for
the data to be summed automatically, based on the four categories when I
insert it for month X. I am currently using

=SUMIF(INDEX($H:$H,N93):INDEX($H:$H,O93),N94,INDEX ($M:$M,N93):INDEX($M:$M,O93))+SUMIF(INDEX($H:$H,N9 3):INDEX($H:$H,O93),N94,INDEX($N:$N,N93):INDEX($N: $N,O93))

Whe
Column H is where the category definition is for each line item
N93 is the cell that tells the formula what the starting row is
O93 is the cell that tells the formula what the ending row is
N94 is the Category that is being summed in column H
Column M and N is where the numbers are that are being summed.

I have since migrated to Excel 2007 so the SUMIFS command is available now.
My question is - is there a more elegant way of doing this? Also, I currently
have to physically input the row number into N93 and O93. The problem is that
if I insert data into a prior month, it obviously changes all the start and
end rows for the months below and I have to fix them manually. Is there a way
to fix the start and end rows absolutely so that if I do insert data in a
prior month the reference in N93 and O93 will automatically update?