Windows 7 Search *.reg file to change file association for *.txt extension and/or txtfile type?

Yes, I could change the file association via Win GUI or use some third party tools.

However I prefer to do this directly in Registry by a *.reg file (in Win 7 64bit).

How can I set my editor "D:\tools\editor\myeditor22.exe" as default editor when double clicking on a file with *.txt extension?

How can I set my editor "D:\tools\editor\myeditor22.exe" as default editor when double clicking on a file of "txtfile" file type?

Again I would like to get the corresponding *.reg script.
And I am not talking about the "Open with" context menu but the double click action.

Peter