Soon I finished implement all options I needed in my grid but I have to do implement "grouping" option by selected rows. So it's possible to grouping rows by column but I just need to select 3 or 4 rows and click to "grouping" for group they in onw row you know ? and when we click to + I see all my rows....

Sorry of my english ^^ but in basic sentence : I need to grouping only selected rows. It's very important for me, do you have an exemple for this please ? Or how Can I do it alone, it's really possible ?