Not sure if this helps, but I did the AAWT Kosciuszko to Hotham last November, travelling one-way by public transport. A lot of tricky connections and It takes a couple of days, but it was fun. So, you could travel from Thredbo to Omeo by public transport, but you'd have to work out transport/car shuttle from Omeo to Buenba Creek (I just parked at Hotham). Might not be worth the effort for you, but the following is from my notes. Check links for reverse times, though I walked north-south because connections were better that way.
Hotham to Omeo: M, W, F only, bus dep Hotham Heights 2:25 pm arr Omeo 3:20,
http://www.omeobus.com.au, $5.40
Omeo to Bairnsdale: Dysons Buslines - contact 51521711 or 0418 576251, Depart service station opposite Golden Age 6.30 am M & F (arr 8:35) or 8 am (Tu, W, Th & M-F School hols) arr Bairnsdale Station 10:30, ptv.vic.gov.au/route/view/1440
Bairnsdale to Cooma: Canberra bus dep Bairnsdale station 11:15 am, Mon & Thu (Sat school hols only) arr Centennial Park/Bombala St Cooma 4:10 pm,
http://www.vline.com.au, bookings online, $38.80
Cooma to Jindabyne:
http://www.snowliner.com.au, school bus dep around 6.30 arr 7.15 (must ring (02) 6452 1584 to arrange) also have afternoon buses. $15
Jindabyne to Thredbo: Wally (
http://www.snowlinkshuttle.com.au, (02) 6456 1591) does the morning and afternoon school bus runs and can pick up 7.30 arr 8 am. $20