I have a line, and I want to put 4 squares on it. I dont care about the distance between them, just want to divide them equally and space them. how do I do it?

In nanoCAD you can do it by using 'Array by Path' Tool.

First select the object press Enter and select the path or the curve. 

From the Properties panel select the Method : Divide and enter 4 in the Items

You can also do that from the options in the dynamic input or the Command Line.

Press Enter to commplete the command.

The line will be diveded in 4 parts automatically and 4 rectangles will be placed accordingly.