Value error on CountIf looping through closed workbooks - excel

Question

I want a function that loops through closed workbooks having some parameters given from cells of onother workbook. The aim is to count the number of presence of people in some locations considering a month.
Option Explicit
Public Function ContMonth(colleague As Range, location As Range, month As Range) As Long
Dim nameMonth As String
Dim nameLocation As String
Dim nameColleague As String
Dim rangeLocation As String
Dim stringMonth As String
Dim file As Variant
Dim count As Integer
nameMonth = month
nameLocation = location
nameColleague = colleague
Select Case True
Case nameLocation = "ponte milvio"
rangeLocation = "$A$2:$B$2"
Case Else
rangeLocation = "null"
End Select
Select Case True
Case nameMonth = "January"
stringMonth = "-01-2022"
Case Else
stringMonth = "null"
End Select
file = Dir("C:\Users\sbalo\Desktop\Test\*.xlsx")
While (file <> "")
Do While InStr(file, stringMonth) > 0
count = count + Application.CountIf("C:\Users\sbalo\Desktop\Test\" & "[" & file & "]" & "Sheet1" & "'" & "!" & rangeLocation, nameColleague)
file = Dir()
Loop
Wend
End Function
Sub Test()
Dim counter As Long
Dim name As Range
Dim location As Range
Dim month As Range
Set name = Range("A3")
Set location = Range("B2")
Set month = Range("B1")
counter = ContMonth(name, location, month)
End Sub
this time giving me type mismatching on line:
count = count + Application.CountIf("C:\Users\sbalo\Desktop\Test\" & "[" & file &
"]" & "Sheet1" & "'" & "!" & rangeLocation, nameColleague)