Duplicate Screen with eGPU dock

Hi. This is possibly a really stupid question. I’m trying to find a way to render the image on the eGPU and display it on the internal display. I can’t use windows’ built-in duplicate display because they’re 2 different GPUs, and I can’t get Lucid to install because it’s a laptop. I can use the internal display to leverage some of the eGPU’s power but it’s a Sandy Bridge CPU so I can’t play any games that require DirectX 11. My current best idea is to buy a USB capture card but that would cost more than the laptop so I really don’t want to do that.I hope this is the right forum category, any help would be appreciated. Thanks