Hi Ljoe1969,
AFAIK, there is nothing special about a 2d Autocad drawing. Any cadcam program can make use of lines and arcs drawn in Autocad to create a gcoded program.
Having said that, there are many factors that come into play, because the variety of tasks that we invent for our machines to do is almost limitless. This creates complexity, and nothing is ever as simple as it looks on the surface.
Take your typical drawing of a part just laid out in Autocad, or wherever. Unless you have a zero-width tool, your drawing is useless for machining with, because the tool is required to follow the lines you have drawn, at a fixed distance, on one side or the other. Yet this fixed distance is variable, depending on your choice of cutter diameter.
That cutter choice cannot simply be any size you dream of, either. Total depth of cut, amount of material to remove, corner radii,, etc, can force you to sometimes use cutters that are longer or shorter , bigger or smaller than what you have used at other times.
The cutter choice itself then forces certain constraints on you about how deep you can go per pass, etc. Your Autocad drawing has no information about the Z axis movements of your tool.
Your Autocad drawing also contains no information about the roughing stage, where the tool has to clear away excess stock that is not near enough to the profile to be cut away in one pass with the tool.
So unless you are cutting narrow kerf with a laser or waterjet, there is really very little accomplished by having only the bare Autocad drawing ready. A simple conversion of the part outline to gcode gets you nowhere.
There, now you are caught right up with the rest of us, or else we wouldn't be on a site with zillions of banner ads for different cadcam systems
Have you run any demo software yet to get a feel for what is offered, versus what you want to pay? How much work will you be doing? Are you going to try to make money using your router?