Hello Marco,

Here is how you do it in VX:

In the drafting module, I assume that you have a layout of a 3D part.

1. Select Insert > 3D View > Sections
2. In the options form under Required Inputs, select "Revolved"
3. Select the side view with the hole.
4. Select the base point so that you are on the centerline of the hole.
5. Pick vertical.
6. Adjust the Base arrow or the Align arrow so you are not sectioning all the way through the part.

Let me know if you need images.
Good Luck!