making it specific to the system that you are using (example, in my old system, I created a function to enumerate every missile within a given radius of a given point, using that you can modify them (like slow them down, or destroy them))... given that the system allows enumerating the missiles, you can create a periodic check within each missiles position to determine if it will be colliding, if yes, destroy them...
since you linked two systems, well which one will you actually be using?... also, its better to just ask the maker's of the system to do it...
I can guide you maybe, but not do it totally for you as you want it in GUI which I really don't like doing anymore...