A computer program product for controlling an apparatus for continuous casting of metals. The computer program product includes a computer readable medium and computer program instructions recorded on the computer readable medium executable by a processor for performing the steps of supplying a molten metal to a casting mold with an elongated horizontal cross section, applying at least one magnetic field to the to exert an influence on the movement of the molten metal, generating a stationary magnetic field with a variable strength across the elongated cross section of the casting mold in the vicinity of, or below, where the molten metal is supplied, and generating a variable magnetic field in an area of the upper surface of molten metal in a region that is centrally located with respect to the elongated cross section and in the vicinity of where the molten metal is supplied.