Adding List Box To Display Multiple Hyperlinks Per Record

I have a table which contains a number of records, each with a load of different columns. However, the new way of doing H&S splits Risk Assessments into Short and Long COSHH forms. Each experiment only has one Short form, but can have from 0-20 (or more Long). I need a way of adding a box to the form that will return all the associated Long forms for that particular record. I have tried using List Boxes and Combo boxes as well as creating a separate table for the Long Forms, but it isn't doing what I had envisioned.

List boxes appear to do what I want, however they just dump all of the results from the selected columns into the table. I only want the data for the specific record in question. For example, my first record has 6 Long forms, but a list box basically just pusts a snapshot of the table in there rather than the specific results.

All the Short and Long Forms have to be hyperlinked to the associated documents. I have successfully done this for the Short.