[CONNECT C++] Making a Cell an Annotation Cell

In pre-CONNECT, there was an undocumented function one could use to take a non-annotation cell and make it an annotation cell:

extern "C" DLLEXPORT	StatusInt				mdlCell_setIsAnnotation(MSElementDescrP cellEdP, int isAnnotation);

however, this seems to remain un-documented in CONNECT. It also looks like IAnnotationHandler does not support cells. So, in the CONNECT environment, how would one make a non-annotation cell into an annotation cell? The use of mdlCell_setIsAnnotation() still works...

Thanks,

Bruce