How asymmetrically encrypt under windows ( CLI )

Hi,

How can we (under Windows...) encrypt file (or stdout) asymmetrically ? (best will be with ECC)

I see I'm not alone with this question https://security.stackexchange.com/questions/86721/can-i-specify-a-public-key-file-instead-of-recipient-when-encrypting-with-gpg

Apparently with GnuPG (bin for Windows) it's not working the best, you have first to import the public key ..

And ideas, or alternatives ?

Thanks.