Hi, Hi, Saumur
Post #16 has a dxf and tap file that should do what you need.
Jog mach3 to the Diameter / Start point you need, Then Zero your Z and X axises.
There is no tool offset in the G-code, Should work fine.
Hears a LC LCAM file also, I Cleaned, Optimized and moved the 0,0 "target" to the right side.
Then just click "Post Code" Button will generate the profile to Mach3.
Hope this Helps, Chip