Capture a window and the sound of that window alone

Hello, I am a student.
"I have a computer that has captivate. I only have one computer. I want to record a teacher's (remote) course, while working on the same computer (while recording with captivate Some students have two computers, they record the course (which takes place online) on one computer, and they get to work and take tests on another computer.
I remember that I only have one computer. Captivate is installed on the computer in question. And while captivate is recording a window on which the course takes place, I need to work. All the attempts I have made have failed so far as I realize that captivate is still recording my entire screen. when I open other applications it shows in the recordings. And I want the recording to just focus on the chosen window and forget about everything else.
Is captivate capable of this kind of feat or am I wasting my time with captivate?
thank you for your response in advance.