I am trying to access the Initial holdup composition of a separator in a dynamic simulation. Since it seems that it cannot be done with the VBA functions in Excel, I want to do it with the BackDoorVariable function.

The link to the composition is given by:
FlowSht.1/UnitOpObject.400(V-100)/SepStage.500!:MoleFraction.101.0'

How can I access the separation stage of the separator? My code is:
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Dim hyBD As BackDoor
Dim hyOp As Separator
Dim hyFS As Flowsheet

Set hyFS = Hycase.Flowsheet
Set hyOp = hyFS.Operations.Item("V-100")
Set hyBD = hyOp

Set hyBDvar = hyBD.BackDoorVariable("MoleFraction.101.0").Variable
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It returns -32767, which is the empty value…The composition contains values, so it should return the composition value.
I think the error is in the: Set hyOp = hyFS.Operations.Item("V-100") , because it doesn’t have the “SepStage” part…Is there any way to include this?