Modeling a copolymer

Hello, I have a problem with modeling a random copolymer. I have watched the video on modeling polymers, but it only separates the chain in half with one side one type of monomer and the other half another. I would like to randomize my copolymer with ~95% of one type of monomer and the other 5% with another. I have no expectation for selectivity of this, but if possible have each “molecule chain” randomized to further match reality. like 20 molecules of these random copolymers each being slightly different based on chance. That last part is hopeful thinking, but yeah if you can guide me on learning how to model a random copolymer would be great.

Some additional information: CHARMM GUI has a way of doing this with setting each SRU POLYMER to n=0.95 and n=0.05 and then the total N=100 (SRU). Sadly I don’t have the license for that so can’t use, but atleast helps explain my issue.