Converting existing Commonwealth Rewards points to QFF points

[The Rok]

As far as I remember you can change ONCE every 12 months.

Hi,
I'm about to apply for the CBA Diamond Amex / Visa and will set it up initially as direct sweep to QFF. (It seems that is the only way to get QFF points, i.e. you can't leave them in CBA and then transfer them later)
If after a year or two the QFF points pile up, does anyone know if you can change programs, so that from that point onwards, all new points go to Velocity points for the next year or so.
Would it then be possible to switch back so that new points could then be directed back to QFF at some point in the future?