Bob, I dont seem to recall a way to make that happen.
Remember that YellowFin company wrote the viewer for their products. Kind of what other manufactures have done.
A third party developer then wrote a program to convert the HB output to the format of YellowFin. YellowFin does not recognize the third party efforts and does not support the converter.
From what I have seen and used in Yellowfin is the viewer of the record for the sonar. A couple of other small tools are helpful in the view but waypoints dont seem to be in the picture.
A couple of other users here are using the converter and the viewer so they may be able to also post something.
Humviewer is a great program and does have good functions.
So maybe between the two you will get the best of both worlds.
Chuck (sonar2000)