El ejemplo, de hecho, viene documentado:
Cita: '================================================= =================
' WORK WITH FORMULAS
'================================================= =================
' a. create a session variable
Set FormulaFieldCollection = Session("oRpt").formulafields
' b. create the session variable, in this case oFFC, and point
' it to the collection of formulas in the report
' (FormulaFieldCollection)
set session("oFFC") = FormulaFieldCollection
' c. point that session variable to a specific index in the
' collection
session("oFFC").Item(10).text = "'"&request.form("numpedido")&"'"