Can I use my Website SSL cert to encrypt local files?

I’d like to encrypt some stuff locally but using my website SSL cert

In other words, it would be as if I had encrypted them on the site using the site key and cert but do it through gpg4win

The website would also be able to decrypt these files in needed

Is this possible?

If yes, how can I do it? (I’m not fully getting how this method of encryption works)

Many thanks