We enter the STAR as defined on the flight plan. If it looks as though the opposite runway will be in use, it is usually a simple matter to find the same STAR designation but for the other runway.
As an aside, I think it is high time that runway in use was promulgated on METARS and VOLMETs. In the case of the latter; we don't really need to hear three cloud levels do we? Why not give just the lowest two and leave space for runway in use?