The dynamics of a magnetically forced conducting fluid in confined geometries is studied. A pseudospectral method with volume penalisation is used to solve the resistive magnetohydrodynamic (MHD) equations. A helical magnetic field is imposed via boundary conditions, which generates a response in the velocity field for large enough magnitudes. Different helical structures are observed in the flow depending on the magnitude and direction of the forcing and the cross-sectional geometry of the fluid domain. A computational technique for finding a solenoidal vector field which can be used in complex geometries is also proposed.