you have to apply h1b transfer if company B is subjected to h1b

there is no way to apply for new h1b at this time if company B is subjected to h1b quota.

as a common sense, you are not eligible for h1b transfer since you are not h1b holder, so don't hold too much hope on this application.

It's likely that your application would be denied so I would wait for h1b approval notice, instead of receipt notice as allowed for normal h1b transfer, before I join h1b