Is there any way to automatically accept SSH host keys—even when keys are changed—in PuTTY?

We use some software that will SSH to a bunch of machines and do something. The problem is in our test lab, the virtual machine’s are re-new (destroy and re-created) very often, so the software will treat the virtual machine as new, which it is, and will fail because the authenticity of the host cannot be established. I was told to manually PuTTY in and accept the host key, and after the software will be happy.

Doing this with a few hundreds virtual machines is not fun.

So, I want to know is there any a command tool that I can automate to accept the host key for PuTTY? We are in a closed lab, so I am not too worried about security.

I know there are some solutions for Linux environment, but this one is Windows.