VBA Vlookup function returns wrong values

Hi I am using vlookup function in VBA codes to import data from one excel file to another. The source file opens successfully. The code runs with no error messages. But the imported value are not correct.

The expected values imported are attendance percentages from the source file. However, the imported value are all zeros only. I have highlighted what I think is the problematic code in red.

The table array in the source file is A16:I55 but it can be shorter as number of students varies so it could be A16:I50. I set it as I55 so it will be sure to include everyone as the length of the table will not exceed I55. The lookup value is B4 which is the student name. Since i have to look up many students, I have set up the dim i as integer function to loop the Vlookup function. Could you please suggest what could be wrong with the highlighted code below so that it caused the aforementioned problem?

Thank you very much!

Sub button()

' Get customer workbook...
Dim customerBook As Workbook
Dim filter As String
Dim caption As String
Dim customerFilename As String
Dim customerWorkbook As Workbook
Dim targetWorkbook As Workbook

Set targetWorkbook = Application.ActiveWorkbook

' get the customer workbook
filter = "Text files (*.xlsx),*.xlsx"
caption = "Please Select an input file "
customerFilename = Application.GetOpenFilename(filter, , caption)

On Error Resume Next

Set customerWorkbook = Application.Workbooks.Open(customerFilename, UpdateLinks:=False, ReadOnly:=True)


' copy data from customer to target workbook
Dim targetSheet As Worksheet
Set targetSheet = targetWorkbook.Worksheets(1)
Dim sourceSheet As Worksheet
Set sourceSheet = customerWorkbook.Worksheets(1)


Dim i As Integer
For i = 4 To 43
   targetSheet.Cells(i, 11).Value = "=VLOOKUP(targetSheet.cells(i, 2),sourceSheet!R16C1:R55C9, 9, False)"
Next i



customerWorkbook.Close SaveChanges:=False


End Sub