"Remote Desktop" but only one window?

I apologize if this has been posted before. I tried to search for it, but wasn't exactly sure how to word what I am looking for. I am looking to have just 1 window from my pc show up inside my quest, that I can pin out of the way no matter what I am doing. 

Ultimately, I am looking to stream game play to TikTok, but would like to have the chat window from TikTok Live Studio show up in my headset.