creating four symmetric holes from one along two axis I want to create four symmetric holes from one along two axis. While the object(a box) itself is fully symmetric along the Y axis, but is only partially symmetric along the X-axis, so I can't just use one mirror modifier and select both X and Y axis of symmetry. See the picture:

What is the proper way to deal with the partial symmetry along the X-axis and create the second symmetrical hole on one side of the box? At the end I want to have this - if I change the original hole - all other 3 holes change itself automatically.
icosphere cut by a cyclinder

cylinder is mirrored along icosphere