Cord ??? ?

Hi, one of the runners broke today on my vertical blind, it seems to be the main one with a cord knot in one hole and a cord knot in the second (both knotted in one runner) now I have unthreaded all the runners to remove the broken one as put it at the end, then rethreaded them all again, my problem is, without putting a knot on both cords, what can I do as an alternative? Thank you Steve.
SteveO, March 2020