Add Assembly Component Property in ProcessExecutor

Hello,

An assembly product “Assy_1” has a assembly step “Part_1”, and “Part _1” has a assembly step “Part_2”.
“Part_1” has a step property “Destination”.
In Process Executor, I tried to assign “Buffer_1” to property “Destination”, so I wrote,
“GetAssemblyProperty; Destination from AssemblyOrder as Destination”
"Assign AssemblyOrder.Part_1.Step.Destination = “Buffer_1"”

But Error “~SetPropertyStatement: Unable to assign value to AssemblyOrder:Part_1.Step.Destination; the property does not exist” occured.