This paper describes an approach to the control of non-zero set points of a class of uncertain linear systems based on the theory of ultimate boundedness. Unlike previous works, here it is not required that uncertainties satisfy the so-called matching conditions. A sufficient condition for the existence of a state transformation (which can also be extended to non-linear systems) for the transformation of the mismatched system into a matched system is derived. A control low for controlling non-zero set points in the new state space is also developed. For illustration, an application to the control of a simple power system with varying load and uncertain parameters is considered. It is seen that the approach of this paper is useful in obtaining a proper state space in which it is possible to prescribe desired set points. Simulation results are presented to show the effectiveness of the controller.