I have been having trouble with the built in Access charts, see this question. Now I am looking for alternatives to the MSCharts that plugin to Access. My initial search on google turned up only noise.
It doesn't have to be open source and it can cost real money.
I don't have any specific answers to give you on this question other than to suggest that you export the relevant data to Excel and create the charts in Excel.
See the following URLs for some sample code to export the data to Excel
Modules: Sample Excel Automation
Modules: Transferring Records to Excel with Automation
Trouble is I don't have any sample code for creating charts in Excel. I'd suggest starting at http://www.mvps.org/links.html#Excel or searching on MVP Excel charts. (MVPs is short for Microsoft Most Valued Professional. Searching with the MVP keyword is more likely to get you some FAQ and sample code pages.)