GCF in the PSS settings

Hello,

I'm setting a PSS simulation for my DDS.

The produced frequency is fCK/(2^N)*step, where step is a parameter that I control from the ADE, and N=10.

I would like to set the beat frequency of the PSS as a function of my parameter. In particular, I would like the beat frequency to be

fCK/(2^N)*GCF(2^N,step)

where I called GCF the greatest common factor between 2^N and step.

Is there a GCF function? I didn't find anything similar in the Virtuoso Visualization and Analysis XL User Guide. I really need a GCF function to keep my PSS settings correct for every value I assign to my parameter.

I hope you can help me.

Thanks a lot!