Forms Data Controls :: Manage A Datagrid Within Another?

I have a table in my database with three fields: COURSE_ID, PERC, DATE.I need to display sets of rows based on the date, the number of rows in every set will be known at run time, the same as the number of sets, so I was thinking about adding two buttons (one to add a set and another to add rows in that set)

I know that working with GridViews will do, but do not know how exactly, maybe one gridview for the sets and a second gridview (inside the first one) for the rows inside the sets.

<Add Set>

<Add Row>

Set 1

COURSE_ID PERC DATE

2 10 2010-12-02

3 90 2010-12-02

Set 2

COURSE_ID PERC DATE

3 90 2010-12-10

4 10 2010-12-10

Set 3

COURSE_ID PERC DATE

3 80 2010-12-15

4 5 2010-12-15

5 15 2010-12-15

Set 4

COURSE_ID PERC DATE

2 100 2010-12-18