'Na si wah wu ji pa ban!'
I think it roughly translates as 'If I had a million dollars...' and so the song tells us what the personae might do with the money if he/she had it. It's in a similar vein to the song 'If I Were a Rich Man' from 'Fiddler on the Roof' (or its latest pop re-incarnation...)
By the way 'na si' also means 'rice' in Malay - it's a case of coincidental phoneticallity!
Joker who spends his free time milling around NUS pretending to be a student...