You need the Id’s of the Sheets in Excel, to do that use the Element.Id node and export it to Excel.
Now if you read the Excel file in Dynamo make a code block and type the following.
Revit.ElementSelectorById (case sensitive)followed by (Id,true)
What it will do is read the Excel data (your Id’s and select the corresponding element (Sheet) now you can get and set the parameters.