Is it possible to reach an propertie of an other item in a symbol.

Let me explain:

We have a symbol that we use multiple in an other symbol (some switchobjects in an baytype). With the baytypesymbol we built a single line display.
In the symbol of the switchobjects we have defined a pictureswitchFunction witch will call up the control dialog for that particular bay.
The bay variables are replaced with the linking rules.

Because we could not export ($_property) the param property of the pictureswitch outsite the baytypesymbol. I uses the Pictureswitch in combination with variable {e.g. X01}
So when I click on the symbol it runs a small VBA code which will read the stationname of an hidden object "Baynumber" in the baytype symbol and write it to the Index var for the Pictureswitch
The stationname property was exported ($_) .

In VBA script I used SubstVarStr = obelem.parent.item("baynumber").stationname.
It worked for the first instantiated symbol. But for the next bay it does not work. because "obelem.parent.item("baynumber").stationname" is allways refering to the first instantiated symbol
So than I figured out that the parent of the switchobject is not the baytypesymbol but single line  display

Is this the right approach. and if so How can I reach an property from an other item in a symbol with VBA. And if not what is than a beter solution

Thanks in advance