Activate another open workbook and sheet

I have a main spreadsheet that opens another spreadsheet and copies that second workbooks directory to a cell on the main page. I am trying to be on the main workbook and activate a certain sheet on the second workbook, which is determined by a data validation list of the sheet names. I want to have the sheet be selected, and the user clicks a button and it will activate the directory in D6 and the sheet in D8 of this picture.

I saw somewhere that said something like the code below would work, but i get an error on the Workbook activation line. (error: Run-time error '9': Subscript out of range)

  Dim Entry As String
    Dim Filepath As String


    Filepath = Range("D6").Value
    Entry = Range("D8").Value


    Workbooks(Filepath).Activate
     Worksheets(Entry).Activate

Do i need to be using the Workbook object or will this work with strings?

Not path but name, not workbook but Windows

Sub a()
 Dim Entry As String
    Dim Filepath As String
    Filname = "Cartel1.xlsx" 'Range("D6").Value
    Entry = "Sheet1" 'Range("D8").Value
    Windows(Filname).Activate
     Worksheets(Entry).Activate
End Sub