Adding context menu to windows explorer

Hi,
I'm trying to add a contextmenu(adding my custom context menu) to
windows explorer.
This context menu has to be shown for all files and folder
Th new context menu will be like this

M=>M1=> T1
M2
M3


I'm not able to find any suitable example for adding context menu to
windows explorer?
I'm planning to write this in C# (.Net2.0)
I saw some examples like shell extensions, is it ok use shell
extensions?
Kindly help me out

Thanks,
Sony