Mirroring a data range
 

Hi
I have two worksheets in the same excel file.
The first one is the one were I made a lot of changes, as input data.
In the second one I have to use the data from the first to make some
calculation.
My problem is that I have to add some new rows in my "input" data. How can I
refer this so that when I add a row in the first sheet this will be copied in
the second sheet?
Try a small grafical explanation
First sheet Second
A A
B B
C C
D D
If I add a new row in the first
A
B
X
C
D
this has to be "mirored" also in the second sheet