Formatting a chart in Powerpoint to update automatically

I want to set up a 12 month rolling chart that will automatically remove the
oldest month, insert the new month, and apply blank cells for input of the
new data. I am told it is possible, but can find noone that know how. The
charts I am working with are standard PowerPoint line graphs. I am able to
program macros in Excel but have been unsuccessful with attempts to program
macros in PowerPoint. Any knowledge is greatly appreciated.