Software for complex g-code generation

Guys, I'm almost building my CNC. I came up with a question. Say I have a complex geometry that needs to have some drawings on top. Assuming I have the slt drawing of this figure.
This geometry may be flat surfaces, curved, etc. .. If I wanted to just write or draw little lines on the surface .. the CAM software can do this?
In other words, I have as input the complex geometry and the lines need to be drawn on the surface (if I can do engraving on the surface where I need to pass the drill).
In the end, cnc machine would just go the route of the line on the surface (being any type of surface: regular, irregular, etc).
I saw the videos on youtube, usually the part to be machined is a rectangle or a general surface. In the CAM software I can insert my custom initial geometry?
Look for example this computer mouse, I would insert the STL model of the mouse as initial geometry (which will be machined) and the STL model of the mouse --->already machined<---. Finall, the CAM software would generate just the drawing on the picture (the skull **)
Can CAM softwares do it (just engraving on the general surface)?
Attachment 252890

Thank's