HI Mike. Please do not "simplify" the drawing of your complex wing. You will only build more errors into your CG calculations.

There is a small program that is available, to do exactly what you want. It is specifically designed for complex wing shapes like yours. It's easy to use, there's plenty of free tech support and you get accurate solutions in just a few minutes. It will give you the CG and Neutral Point of your plane, so you can easily tell how stable the plane will be and it lets you adjust these values, so that you fine-tune the performance of the plane to your level of flying skills. And, all of the math is done for you.

Look at www.rcaeronauts.com, for a good discussion and the answers you need.
Best of luck.