How i can make hack (internal) VAC Undetected

No software will make detected cheat undetected.
If you're a programmer, you should have enough common sense to understand what people mean by adding junk code. Pretty sure it's enough to just disable optimization and adding junk code to make cheat ud as masterpaster Joplin has made ayyware ud more than enough times.
If you're unable to do such simple thing, just use someone's else work.