I know it's possible to leave some empty holes on the hub, but I've never seen it done with empty holes on the rim. You would probably have to leave those 4 holes equally spaced from each other, in a cross or X pattern. But if you leave one hole empty between two spokes, then one of those spokes will be inserted into a hole on the rim that will point the wrong way out. Hhhhmmmmmm...
I'm guessing it can be done if you have wheel trueing skills and if the rim holes are nearly identical to each other (they don't "point out" much).
Hugo