Tech help!

No you won't be able to. Your internet connection should have a VPN so that the BBC servers think you are connecting to their servers from the UK.

ah no... not quite right. With the VPN just on your PC or in your browser, you'll find that you'll effectively create a firewall between your wifi and your Chromecast.

What you actually need to do is buy a router that can host your VPN on it and then connect that router signal to your Chromecast. Such routers are usually high end though ($150+) particularly if you want one fast enough. And you will need one fast enough.

Unless you've got a really fast original connection, both the VPN and then then casting itself are going to take that speed way down. My experience is that you get lots of buffering even if it does work. But then I didn't have a great connection. If yours is much better, maybe it would be worth a try.

I found a good old HDMI cable worked just fine, cost waaaaaaay less and didn't have me tearing my hair out trying to figure out how it worked.