Is this for AMHA or AMHR? Ammy classes that do not lead up to Championship classes do not count according to page 328 of the 2008 AMHR Rulebook.
It is also noted that for example - Hunter class, where there is no Championship classes - on page 327 it is noted that if a horse/pony gains 70 points, special provisions exist for performance categories and upon the recommendation of the National Office a horse can achieve HOF status.