can anyone tell me the difference of ProPatternHeader and PropatternLeader?

i am now trying to initial a function to get the dimension of pattern feature member, i can get the pattern member dimension of dimension pattern, direction pattern, but not point pattern.

i'm not sure what the problem is ,maybe it is the handle that i'm using is wrong.

for now i'm using:

status = ProPatternHeaderGet(&pattern,&pFeature); 

it can successfully get the pattern member dimension for dimension pattern and direction pattern, but not point pattern.

as the snapshot below, the dimension of pattern member is stored in sketch, now i don;t know how to get the sketch feature here.

i tried ProPatternLeaderGet() function, it doesn't work.

what is the difference between ProPatternHeader and ProPatternLeader, what function should i use to get the handle of the sketch for point pattern.

many thanks for you all.