Designing a pcb for cnc routing

Hi everyone. I am making my first attempt at a pcb using a cnc router. Ive designed it using proteus and i am trying to get the gcode from coppercam.

The design issue i now have is that one of the tracks is high voltage(220Vac) which im going to solder over to make it thicker.

What i need to o now is create a better clearance around the path. I understand the successive contours but it applies it to every track which takes time and not necessary.

Is there a trick i could use in either software to create a clearning around the thicker tracks?

I would look at a free program called flatcam, it imports gerber files and you can do isolation milling with it.
There are some videos of how to use it and a good instruction manual.
It's. 1000times better than coppercam.
The trick is with CNC pcb milling is getting the depth of cut correct. I use a 0.2mm bit and do 2 passes to give .4mm clearance. It's all about getting the cutting depth, the way I cracked mine was just to lay out A couple of dummy tracks different sizes side by side then used flatcam to prouduce the g-code with a set depth then cut them out and used a loupe to measure the track width. Say if the track was sized at 0.4mm and if it measured smaller than that then your cutting depth is to deep again if it came out lager then cutting depth was not deep enough.
I now use that setting I got for all my boards and get perfect results.

As far as I understand, the OP is asking how to implement different clearance for different nets, HV clearance only where necessary.

I imagine that useful milling software would be able to implement it.

I don't think that coppercam can do isolation milling, not really looked into it when I tried it so may I be mistaken. Flatcam does isolation milling and very easy to set up and carry out. the rest was just some pointers on setting OP'S cnc machine up from what I learned when I first did it