How to use Offset and Counta for Charts

[NoobMacro]

Hi there,
I have a set of data comprised by 4 (rows) x 16 (columns) which I use to create a chart. Every month I need to add another column of data to the chart (new columns are added on the right side to the rest of the data).

I want to create some kind of formula where the chart will automatically pick up the most recent 16 columns of data.

I'm very noob at this, so if you can, please explain very thoroughly.
Thank you very much for your time.

-NoobMacro

 

[tusharm]

As long as your new columns will extend existing series, it can be done with a named formula. [Adding new series must be done by hand or via VBA.] For examples that rely on additional data being in rows, including one that graphs the last so many entries, see
Dynamic Charts
http://www.tushar-mehta.com/excel/newsgroups/dynamic_charts/index.html

You will, of course, have to adapt the example(s) to refer to columns rather than rows.