I am working on a simulation building some copolymers with the prebuilt monomers, however I am having some troubles to connect them, can someone here give me some advise?? I would appreciate it a lot.

Suppose I have 3 monomers A-B-C, and when I make the copoymer it works well, however when I try to make the chain longer it happens that A joins C and start all linear again such as -A-B-C-A-B-C-A-B-C-A-B-C-A-B-C- and so on, however that is not what I would like to have, I would something linear like -A-B-A-B-A-B-A-B-A-B and C connected hanging out from B only all along the chain, it means there is no contact at all between A and C, it is like a comb structure.  Well, I expect someone can be able to give me an advise or a way to make it successful. Thanks a lot, I will be in touch... 

Have you all a good day!!!