Copy privileges from duty to another duty by code

I am making new duties in AX 2012. I need to copy all privileges from an existing role's duties to my new duty. I can drag and drop in AOT but the problem is when I drag multiple privileges from one duty to the new duty AND some privileges already exist in the new duty, the copy cannot be completed. Then I need to copy the privileges one by one. Because I have to copy a lot of privileges I was wondering if there is an option to do this by code. Can somebody help me for this?

Regards

Luk