Inside your cpp:

Code:
UCHAR (* CElementoInstruccion::Criterio_Ordenacion[5])(const CElementoInstruccion &, const CElementoInstruccion &) = {
  STEP,
  INSTRUCCION,
  ELEMENTO,
  DISTANCIA,
  TRAMO
};
or, if you want to null-initialize it.

Code:
UCHAR (* CElementoInstruccion::Criterio_Ordenacion[5])(const CElementoInstruccion &, const CElementoInstruccion &) =
{0};
Not entirely sure what you are doing is the best approach though... Too tired to think right now...