This paper considers a robust output setpoint tracking problem for a m-terminal power flow controller (PFC) for meshed DC micro-grids. The PFC is a power electronics device used to control the power flow at a node in the meshed grid, and may act as a DC circuit breaker. The system is modelled by state-space bilinear dynamics coupled with a polynomial output. In the proposed design, the plant is first extended with an integral action processing the regulation error. The cascaded model composed of the plant and the integrator is then stabilised using a saturated state-feedback law, designed with a forwarding approach. An anti-windup function is added to cope with transient saturations. A tuning method is proposed to set the controller gains along the available degrees of freedom with respect to a cost function. The stability of the closed-loop is guaranteed for any compact set of initial conditions and for small parametric variations around the nominal set-point. Experiments have been carried out and these properties are successfully assessed on a tenth-scale experimental setup.