Devices based on direct digital synthesis (SDD) have become a very attractive tool for engineers and scientifics who develop electronic instrumentation, being each time more used than analogic systems for signal generation because them offer advantages in performance and ease of manipulation of the parameters of the signals. In this work we present the implementation of the SDD technique in order to generate arbitrary signals with the programmable waveform generator Agilent 33220A. By means of a macro developed in Visual Basic, which is executed from Excel, the data of arbitrary signals are sent to the generator through the general purpose bus interface (GPIB). As a particular application of the method, we present the digital direct synthesis of the control signal for the oscillations of a velocity transducer used in transmision Mossbauer spectroscopy.