Crossrefencing table for new data/Unique data

Hello All,

Hope all of You are fine and doing well.

Well i am facing an issue in cross referencing two table in a workbook, sheet "Clean Data" contains data of trainees who had completed our courses and "New Entry" contains data i extract from our Learner Management System online quiz. What i want is that the when i paste the extracted data in "New Entry", some how i know which data is new and which already exists in our "Cleaned Data".

The issue is that i can search with the user name column, but some users complete two different sessions over a period of time so i also have to check the reference for "Session Name" in both. What formula of function should i use in Column D of Sheet "New Entry so i get to know new data.

I am attaching the example excel file of some could help, i would much appreciate it.

I tried to nest vlookup in IF function but vloopkup on returns 1st occurrence of value so it does not help much, please help me out here.