I'm not sure Analogue-X's expo is correct.
However,
Select the object you want to export.
Make sure it has a 'positive' attribute.
Create a prim.
Make sure it is NEGATIVE.
Bury it in your first object.
Group the pair as boolean.
Click on the [C] icon.
Export to wherever.

You find that differing formats work better than some.
EG: Try exporting as OBJ, DFX, & 3DS and see which gives you the best result.

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And in my final hours - I would cling rather to the tattooed hand of kindness - than the unblemished hand of hate...