Reversing only the vertical axis in a diagram
 

In an excel-document I have data that generates a diagram in another document.
These data have to be put in with the newest information on top so that one
just put in new sheet rows with new data, and after that one can mark a new
area from which the diagram should be generated.
When the data is in this order the diagram is generated so that the newest
data is to the left and the oldest data is to the right, but I would like it
to be in the other way (the newest data always to the right).
I have tried to mark the diagram area and click on Chart Tools - Format -
Plot Area and chosen vertical (value) axis, chosen Format Selection. Here I
have clicked the "values in reverse order"-box.
This changes both the vertical and the horizontal axis, and this is not what
I want. The horizontal axis should always be on the left.
So - how do I do to just reverse the vertical axis (along with the staples
of course).

Thank you in advance for your help