uhh.. which sample is C64Face... is this sample still part of the API package?
I don't see it in the SDK any more.
There also used to be a video by the dev of Actiface showing the steps, but I can't find it any more.
Do a search in this forum for "custom font" and you'll probably find enough to get started.
The Analog font sample uses a custom font (see samples/Analog/source/AnalogView.mc).