We present preliminary results of a modelling campaign based on HST eclipse observations of the wind-formed C IV resonance line in the eclipsing nova-like variable UX UMa. Within the framework of a simple kinematic accretion disk wind model, we are currently able to reproduce the shapes (but not the strengths) of the observed line profiles away from and during eclipse, as well as the behaviour of the integrated line flux light curve. The most important aspect of our modelling is that it suggests the presence of a vertically extended, relatively dense and slow moving transition region between the disk photosphere and the fast wind.