Information retrieval via Dynamo _return Excel to Revit: Parameter is not a chain ... Element.SetParameterByName

Good morning all,
I block on a Dynamo script
The problem: I need to extract the base surface from a generic model used as Floor Hole (this Floor Hole has an irregular shape), (there are several Floor Holes, all of different shapes),
My approach is to recover the base surface, via Dynamo
With the script I manage to extract the info of the element whose surface, I export it in Excel, it works
On the other hand when I want to re-import the Excel data (only the Surface), Dynamo indicates to me that “the storage of the parameter is not a chain”
_Does this inspire you?
I had heard of lists, but here I do not see
_Do I have to add a particular node between “Element.SetParameterByName” and “SelectModelElement”?
_Do I have to convert my Excel file?


Thanks in advance for your suggestions
Christian