Runtime bridge creator

Hi!

I am making a level editor for my game and I need to be able to create bridges very easily. Just like doing something like this.

You place Point A and then Point B and when Point B is created, it spawns a bridge. But then if you click either Point A or Point B, you can move it and then the bridge moves with it. My question is, how would I do something like this? I kinda got the first thing working with the bridge spawning. But how would I do if I need to move it around?

Thanks in advance