Train geek here...
msb0b is corrent, according to the timetable published by Odakyu, Romance Car Hakone No. 23 departing Shinjyuku on 12:40 p.m. is not VSE 50000.
According to the timetable, VSE 50000 Romance Care are scheduled for:
Hakone No. 15
Depart Shinjyuku 10:40 a.m.
Arrive Hakone-yomoto 12:10 p.m.
Hakone No. 29
Depart Shinjyuku 1:40 p.m.
Arrive Hakone-yomoto 3:07 p.m.
However, the timetable by Odakyu indicates train type of Hakone No. 15 departing Shinjyuku on 10:40 a.m. can change. There is no gurantee that Hakone No. 15 Romance Car will be VSE 50000 on the day of your trip.
Hakone No. 29 departing Shinjyuku on 1:40 p.m. is indicated as run by VSE 50000 every day.
Also, Hakone No. 13 departing Shinjyuku 10:00 a.m. arriving Hakone-yumoto 11:23 a.m. is indicated as run by VSE 50000 every day.