Hi Oliver,
I just had a play with this and I think you’ll find that where Cubasis pastes parts (or events or whatever they’re called here) depending on which track you have selected. So if you copy parts on tracks 1 to 3 position cursor where you want and select track 1. Parts will be placed at that corner. If the subsequent tracks are the wrong type, Cubasis will skip them or create new ones ( I think)
Rob