Qualtrics: How can I display a personal image of a participant, next to a random other image they need to compare?

For a study of hiring bias, I want employers to compare and rate 2 CV's. One CV will be of a person they met before, another will be a random other real CV. There are 500 real CV's in total in my library.

In question 1 I will ask them their own unique study IDnumber, which I know. Imagine in question 5 I ask the employers to compare the CV's. One CV is always their own unique CV they need to see (so if ID = xyz, then show CV xyz). I want the CV next to the unique CV to be random.

I want to do this for 500 participants, and make sure that the randomized CV's are only used once for the random display.

Can I save the random CV in an object, so in question 6 I can focus only on evaluating that CV?

I am new to Javascript, but know people who can help me out a bit. I know R though.