ORIGINAL: shd3920
Photo 1: Small hole on needle valve
Photo 2: Where set screw should be
What I think you may be saying is stick the allen wrench into the hole and tighten the set screw.
You'll need an Allen wrench to tighten the set screw on whatever you choose to use for your extension. For the extension, you may use a piece of music wire of the appropriate diameter OR you may want to use an old Allen wrench as the actual extension.