The shared Star Alliance lounge is in the Non-Scengen area, so unless you fly outside the Schengen area you can't access it. There is a Lufthansa lounge which you can access as *G, it is if I remember correctly in the next satellite so it is a bit of a walk.
As long as it is *A lounges, SK you can access them directly no passes needed. But it would require SK to inform a bit better. No signs at all?
What is happening to the CDG lounge? Refurb?