Best option is to do via Document Manager (you need to obtain a free key for that from SOLIDWORKS).
But there are other macros that can do that same thing with only drawback that macro would open the files and export properties. Best thing is that macro can automatically open/export properties/close files and you only need it to point to the folder containing files.
I've posted a Document Manager Toolkit on my blog that includes several common operations, including reading properties. You supply the license key. Hopefully makes your project simpler.