Can anyone tell me why Excel wants to try an append the filename again at the end of this vlookup?

Dim Path As String
Dim FileNm As String
Dim Wb As String

Sheets("Product Receipt").Activate

Path = ThisWorkbook.Path
FileNm = Worksheets("Data Files").Cells(1, "J").Value

Wb = Path & "\" & FileNm

ActiveCell.FormulaR1C1 = _
"=VLOOKUP(RC[-6],'[" & Wb & "]Product Receipt'!R2C1:R25C18,16,FALSE)"

When checking the cell in the sheet itself, the following is what gets entered into the cell:

=VLOOKUP(A3,'[C:\Users\rr140934\Documents\Excel Files\Production Files\Marshall\[1_MSH_ProductionSummary_Jun_28_2012 - Copy (2).xls]Product Receipt]1_MSH_ProductionSummary_Jun_28_'!$A$2:$R$25,16,FALSE)

Rather than:

=VLOOKUP(A3,'[C:\Users\rr140934\Documents\Excel Files\Production Files\Marshall\[1_MSH_ProductionSummary_Jun_28_2012 - Copy (2).xls]Product Receipt!$A$2:$R$25,16,FALSE)

I have tried many different things to get this issue resolved and no help, any thoughts folks?

Thank You