30 mins would be fine for an international transfer in T5 (like tommy777 said OSL-ARN-ORD).
But transfering from T4 to T5 with only 30 mins sounds very short IMO.
The CDG flights usually leave from the A-pier which means you need to go from T4 through SkyCity and pretty much the entire T5 to reach the gate, and then add security to that.

If you know where to go and are prepared for a bit of running you should make it, just.
But there is no marginal for any delays whatsoever.
And do try to get a seat as far forward as possible from LLA so you're quickly off the plane.