particle tracing module: size distribution function

Hello,

I would like to simulate the trajectoires of polydisperse particles in a gas using the "Particle Tracing Module". In order to simulate particles of different sizes, I created an "Interpolation function" using a csv data file containing the measured probability as function of the particle size. Does anyone know how I could apply this size distribution function (interpolation function) to set the particles diameter in the "Particle Tracing Module" ?

Thanks in advance for your help.
Regards, Florian