The main stumbling block of most nonlinear control methods is the necessity to solve nonlinear Partial Differential Equations. In this paper we propose a methodology to replace the PDEs of Interconnection and Damping Assignment Passivity-Based Control with algebraic inequalities. The idea relies on the construction of an approximating integral and a dynamic extension as an alternative to solve the PDEs. Some connections with linear control theory and nonlinear cascade control techniques are also provided.