Greetings.
I am anticipating a flight soon from Canada to Helsinki. I'm looking at a flight sequence of Air Canada to Frankfurt, then connecting on to LH to Helsinki.

I will likely be buying the ticket on AC, thereby the LH portion will be a codeshare on LH metal.

Is there a way, or has anyone insight, as to the possibility of paying to upgrade my Helsinki flight to Biz class. I have done this before on a single LH flight, but that ticket was bought on LH website.

Thanks