Afaik this really can't be implemented in mIRC scripting, at least not with a huge amount of work. How exactly would you implement Dijkstra's algorithm for finding the shortest distance between 2 computers? mIRC doesn't support recursion, therefore you'd have to write a stack container to simulate recursion, thats not fun at all. To implement this correctly (fast) you also need a priority queue, mIRC doesn't have any queues so you'd have to create a queue, but you'd also need heaping functions to make it a priority queue which again use recursion and therefore require, yet again, a stack to simulate recursion. Seems like, with all the container and recursion simulation it would be so slow it wouldn't be worth it.
