Feeding question - from Australia

Hi
My name is Liat and my daughter was born premmature (week 26+5) in Australia (weight 589gr). We've been in hospital with her for 7 months as she got the cronic lung disease after getting NEC. We are finally at home and she still needs oxygen for another few months.
My question is reagrding her feeding. She was breastfeeding but then got an aversion to that so now we are using a special bottle to feed her. But she can only take 30-60ml a day. Her wieght now is 5.634kg and her corrected age is nearly 5 months. We are working closely with the hospital here to try to get her to suck more from the bottle, but the problem is that she is never hungry and makes no signs of hunger either. She does vomit a lot from her feeds (nearly half her feed 2-3 times a day). In total we are giving her 600ml a day (we've reduced it in order to try to get her hungry and want to suck). She is still putting on weight but moderly.
My question are:
1. Do we need to reduce her feeds even more so she doesn't vomit so much?
2. Can we add extra calories to her feeds with a special formula so she at least gets the calories but her tummy isnot so full so much all the time?

Sorry to write in English, it is a bit easier. You can definitely write back in Hebrew as I can read the answer in Hebrew.

Thanks for all your help
Liat