puppet to null

I have a puppet rigged up with duik.  On one part of my puppet I have added some puppet pins and some nulls.  I want the pins to follow the null anchor points.   I have tried to use this expression below to attach the pins to the nulls but it is the pin moves somewhere else on the layer and deforms it instead.  Im not sure why.  I have done this before and didn't have this issue. Anyone have a clue please?

n=thisComp.layer("name of null")
nullpos=n.toComp(n.anchorPoint);

fromComp(nullpos);