Hi there,
thank you for all your help.
In fact after I've implemented a special copy routine in a z-BADI incopy controle I also hat to work on the follow up activity as the z-fields would not save. The reason was that the z-field component was not created at runtime, so I had to create the model node first and afterwards it saved the z-field content as well.
However this was also the change that made the "simple" copy control work. I've deactivated the Z-BADI to test it, and the BADI had no effect. So the whole problem was at the follow-up document.
Best regards and again thank you for your help,
Thea