I'm not entirely sure if this is possible, but I'm not the most informed person. I'll link you to
Calebark's Q & A that's currently going on; he did a three year VCE, so he's the one to ask.
Alternatively, instead of doing that, have you considered:
1. a bridging course - this helps out if you didn't do a prereq or missed the needed prereq for your desired course. This might help if your ATAR was lower than the clearly-in by a considerable amount.
2. studying something else - this will let you study at uni in another course and, granted that you do well enough in the course, may be able to transfer into your desired course. This works best if it's in a related faculty at the same uni to your desired course.
3. study the same course but elsewhere - if you're not adamant about studying in X uni, you could just take the equivalent course at another uni with a lower clearly-in. Also, if in the three years you studied/ worked in something related to your course, you could be admitted based on those merits over ATAR, as you'll be considered a mature-age student (I think - you'll need to check this first before taking my word for it).