You could try isolating the vocal frequencies via the use of filters and EQ in Ozone, but even then there would still be some spill from any instruments in that vocal frequency range. It would be extremely hard to isolate it perfectly - quite near impossible I'm afraid.
Don't give up, get hold of a programme called Iztope RX, it allows spectral editing with which you can remove almost all the unwanted instrumentation leaving the remaining vocals fairly well iscolated.
Don't give up, get hold of a programme called Iztope RX, it allows spectral editing with which you can remove almost all the unwanted instrumentation leaving the remaining vocals fairly well iscolated.
In theory, if you can get hold of the instrumental as well as the version with vocals can do it in audacity... Drag both in - invert phase. Should be left with an acapella - export.
I've never actually tried it but it works in my head...