Embed a file, but never install it?

What's the best way to embed a file in the installer .exe, without installing it?

Specifically, I'd like to include the plaintext .nsi inside the installer file, and extract it with 7-zip whenever I need it (so that I don't have to keep track of which version of the .nsi goes with which release .exe). This will be open-source, and I'd actually prefer if everyone has access to the .nsi script this way.

Putting this in the install section does work, but I was wondering if there was a better way.

File "project.nsi"

Delete $INSTDIR\project.nsi

I embed the .nsi all the time, for simple projects, you can do

Section
Goto +2
File "${__FILE__}"
SectionEnd 

or, you can have a hidden section that is not selected by default