With an increasing number of devices having varying capabilities and with different types of network access mechanisms, an ordinary user will consider various tradeoffs for selecting one particular device over the other for execution of his task in an ad hoc environment. We propose a model for specifying user preferences so that the selection of the best device for the user is automated. Users specify their preferences and constraints qualitatively, which are then mapped on to a quantitative utility model. Preferences can be specified both for user's liking and dislike. We analyze the theory of TCP-nets as a formal model for representing and reasoning with qualitative preferences, and show how it can be used to create a quantitative preference model. Using an example scenario, the application of our model is shown and its utility against simple additive models is discussed