Cloning a value from another layer without pickwhips

Sorry for all the expression questions today! This should be my last (for at
least 15 minutes!) :)

I have two layers. Layer 2 is my source layer. Above it, layer 1 is a null. How
can I copy an attribute (like position) to the null without pickwhipping layer
1's value?

I've seen an expression that looks at the next layer in the composition. So then
just ordering a layer above another in the timeline will automatically copy a
value from the layer below.

A couple of ways to do it:

thisComp.layer(thisLayer,-1)

or,

thisComp.layer(index - 1)

Hi Dan! I just plugged this into a layer's Position:

thisComp.layer(index - 1)("Transform")("Position")

And I got enormous numbers that are nowhere near the correct value.