"New" with NSIS

I'm developing an editor which takes the RTF as their primary file format.

Anyway, I creating an extension, for example *.jag...

My question is how can I add in the context menu of the Windows Explorer (New), to create a blank file of my extension?

Thanks!

I think is in HKEY_CLASSES_ROOT.

Oh, yeah...

WriteRegStr HKCR ".jag/ShellNew" "" "NullFile"