The calculation and dimensioning of the drive systems of a wind turbine (blade pitch and nacelle yaw), from the definition of the wind loads to the concretion of design, great quantities of data must be handled. Here is presented a software based on Microsoft Excel Visual Basic for Applications Macros (2003 version) which extracts the equivalent values and load distribution diagrams, inputs required by the international machinery standards, from simulated load time series. This is done to limit the amount of data required to describe the loads of a wind turbine drive design in a specific wind profile and location. This calculation process agrees the design guideline by Germanister Lloyd (2003 version) and the guideline issued by the International Electrotechnical Commission for wind turbines certification, the IEC 61400. The load transmission applies to the current design of Alstom Ecotecnia wind turbines in the platforms Eco 80 and Eco 100.