Using Polycurve To Create Rectangle Grid

Good evening,
I am attempting to take an excel spreadsheet and create a series of rectangles based off the quantity of rows in the file. I can get that part to work fine but it creates everything in a straight row. My goal is to manipulate the coordinates in a way that will allow me to arrange these rectangles in a grid with a set number of columns and then create as many rows of rectangles as needed.

Unfortunately, everything I am doing is now impacting the quantity of rectangles instead of their locations. As you can see in the screen grab, I have got them offset but cannot get them lined up. I think the issue is the formula to stack them more so than the nodes I am using, but I could use some help. Is there a way to manipulate the list of coordinates to get rows of four rectangles?

It would probably be easier to setup a grid of points first and then create rectangles at their locations.