You meen Jetstreams get highlevel
BEagle is the best one to ask about this. PM or Mil forum
From what I understand you will get credit for the PPL.
You will have to do all the ATPL ground school.
You will be able to use the hours towards license issue P1 etc and P2.
No credit for CPL or instrument.
Unfortunatly I don't think you have high enough hours to jump up straight to ATPL level but the Jetstream hours will look good on your CV later. You will still have to do a Jetstream 3100 series rating civi. We have different engines etc. But they are still a bastard to land.
Best place to read is Lasors on the CAA website.
Good luck
MJ