rageconfig what? files have extensions...
rageconfig.cfg
There's 2 ways to do it.
You can go into windows explorer, go to tools, select text, and then goto advanced and check the box "always show extension", ok it.
Then when you create a new .txt it will show the extension, then you can rename it to .cfg. In this case rageconfig.cfg.
done.
The other easier way is to copy a .cfg to your desktop, rename it to rageconfig.cfg, then clear it out and put the needed cvars in.
Place it back into the proper location.
done.
Edit:
Seems we posted at the same time.