Reference by column name instead of an absolute number

Hi, I have a working macro that performs the following:
1. Selects all the fields in a table in the column "Functional Area" besides the  function  that was selected on the cover sheet (aka. Series_Name);
2. Deletes all those fields and their data in the table;
3. Then un-filters (shows) only the selected function

It is running fine when I refer to the column number of Initiative Summary tab (number 3). However, when I'm trying  to reference by name instead of referring to absolute column numbers, the macro doesn't work.
o      Instead of:
¿      Sheets("Initiative Summary").ListObjects("InitiativeTbl").Range.AutoFilter Field:=3
o      I try:
¿      Sheets("Initiative Summary").ListObjects("InitiativeTbl").Range.AutoFilter Field:=.ListColumns("Functional Area").Index

Could you please help me figure out how to make it work?

Sub Macro3()
'
' Macro3 Macro
'
Dim Series_Name As String

   Series_Name = Range("Cover!$C$8").Value
   
  If Series_Name <> "All" Then
   
     Sheets("Initiative Summary").ListObjects("InitiativeTbl").Range.AutoFilter Field:=3
   
     With Sheets("Initiative Summary").ListObjects("InitiativeTbl")
   
        .Range.AutoFilter Field:=.ListColumns("Functional Area").Index, Criteria1:=("<>" & Series_Name), Operator:=xlFilterValues
   
     End With
   
     Sheets("Initiative Summary").ListObjects("InitiativeTbl").ListColumns("Functional Area").DataBodyRange.SpecialCells(xlCellTypeVisible).Delete
   
     With Sheets("Initiative Summary").ListObjects("InitiativeTbl")
        .Range.AutoFilter Field:=3
     End With
     
   Else
      Sheets("Initiative Summary").ListObjects("InitiativeTbl").Range.AutoFilter Field:=3

End If

End Sub