Automatically add note to cell in dynamic range based on value

Howdy!

I am working on a project containing a table that will track multiple services performed on multiple pieces of equipment. Additionally, I have a hidden table with three columns to identify the equipment: Unit #, Equipment, and Serial #.

The first column of the main table is a drop down list using data validation. The list is from the Unit # column of the hidden table.

What I am trying to do is that in the first column of the main table, when a drop down selection is chosen, I want Excel to automatically add a note to the cell that shows that Unit #'s corresponding Equipment and Serial # from the hidden table. For example, the first row of my hidden table could show 12345, D10 Dozer, 123456789. When "12345" is selected from the drop down in the main table, I would want the comment attached to it to say:

EQUIPMENT:
D10 Dozer

Serial #:
123456789

I've toyed around with a few ways in VBA but nothing is giving me quite what I'm looking for, and a lot of what I'm finding in forums are for fixed ranges or cells, but this main table could ostensibly go on forever as more and more services are performed on the different equipment.

For what it's worth, I also currently have two hidden columns in the main table that are just using VLOOKUP to auto-fill the corresponding Equipment and Serial # based on what drop down was selected in the first column. I realize the solution likely won't need that, but it's there for if I do need it.

I hope I've explained this well enough, but if I need to clarify further I'd be happy to try.

Any help would be greatly appreciated. Thanks for your time!