使用类和文件属性的方法

I'm quite new to using classes and i'm doing some job in Visual Basic Express 2010. I have a some thougts about to how to proceed with my project. The application will go thru the open files in a CAD software (SolidWorks 2012) and check the file attributes and the equations in the CAD file. This is done using API functions.I'm quite new to using classes and i'm doing so