Need helps

Hi all,
I'm a newbie in Flex.
I have downloaded RingChart component and have really enjoyed it.
Really a greate job
Now, I'm trying to do something similar to RingChart component to level-up my Flex's skill. Particularly, I'm trying to draw a ring chart base on the data that has in a data-grid but I do not know which functions (methods) that I can use to draw such kind of these things:
+ Ring with rings inside
+ Space between rings
+ Space between items in a ring
I hope to see advises from you guys.
Any help would be appreciated.

Best regards,
MaiNgaoSuong