To put simply, take a function generator such as a HP 3325B, set the output to 0dBm at 10 Mhz, plug that into the reference input of the signal generator. Then if you want a frequency of 100 Mhz just dial that into the signal generator. If you desire more precision with the frequency than what the signal generator is capable of, just make very slight adjustments to the function frequency on the generator supplying the the reference 10 Mhz.
I would think this could work somewhat however it might not scale linear at the various frequencies set on the signal generator, and the phase noise would suffer. And to determine the actual frequency a frequency counter would be needed.