I did not give any link related to your issue at hand.
Making things for you easier can only based on the technologies/knowledge/skills available to you. That is why I said using AutoCAD itself would be the best bet for you, considering the question you asked. If you really want to do things similar to the one referred in your link (an stand-alone window exe app without AutoCAD installation required), you would:
1. license RealDwg SDK (a few thousands $US). This is easy part if you have the money.
2. Find a way to generate a high quality drawing graphics out of DWG file without AutoCAD. Very difficult work for even a group of talented programmers, if it is possible/doable at all in a development case like yours. The best bet would be that you might be able to find/buy third part component for this, which could also be somewhat expensive.
3. Learn how to program with RealDwg SDK to deal with DWG file to manipulate data in it.
However, if you do it with AutoCAD, you only need to learn how to program AutoCAD (similar to step 3). After all, if you want to controll layer in Dwg file, wouldn't be very logical to use AutoCAD to do it, in most cases?