Is it possible to pause an animation when a button is held down and if so how?
Whatever you can, and want to create is possible as long as you got the talent to create it.
Nonetheless what you are looking for is not difficult, but there are many ways of doing it, all depending how your system is build up, or how you want it to work. The following suggestions should work:
There are hundreds of possibly ways of doing it, but while not knowing your desired effect I will leave you at this.