Randomize: How to enter multiple record numbers into smart group?

Hi everyone,

I am trying to randomize my library for screening of the articles and dividing them between multiple researchers.

I found a solution that requires to export record numbers to excel and use the random generator, also mentioned in another topic in this community.

This works, however if I want to create a smart group based on the record numbers, it does not work.

Each group contains 1600 references, so it would be nice if it was possible to do it at once.

Does anyone have a suggestion?

The tutorial says it must work by using a semicolom between the record numbers, but that does not work for me.

Using endnote X9

Thank you,