Inserting string in formula array function

[jessicsw]

Hello! I've been lurking the message board for several weeks and it's been very helpful as I slowly learn more about VBA.

I've read multiple posts on how to incorporate a string into a Formula Array function, but after being stumped for several days, I think I need another pair of eyes to take a look. I keep getting the error: Run-time error 1004 Application-defined or object-defined error in the formula array below:

Sub FindCAHS()    Dim HS As Range: Set HS = Range("J2")
    Dim refworkbook As Variant
    Dim ref1 As Workbook
    Dim ref2 As Worksheet
    Dim ref3 As String
        refworkbook = Application.GetOpenFilename(".xlsx Files (*.xlsx), *.xlsx", 1, "Select the HS Reference xlsx")
        If refworkbook = False Then Exit Sub
        Set ref1 = Workbooks.Open(refworkbook)
        Set ref2 = ref1.Worksheets.Item(2)
        ref3 = "'" & ref1.Path & Application.PathSeparator & _
    "[" & ref1.Name & "]" & ref2.Name & "'"
            For j = 2 To 3
                If IsEmpty(Cells(j, 10).Value) = True Then
                    HS.Offset(j - 2, 1).FormulaArray = _
                    "=vlookup($F$" & j & "&$G$" & j & "&$H$" & j & ",Choose({1,2},""" & ref3 & """!$C:$C&""" & ref3 & """!$D:$D&""" & ref3 & """!$E:$E, """ & ref3 & """!$F2:$F5000),2,0)"
                    Else: Exit Sub
                End If
            Next
    ref1.Close False
End Sub

When I check the Locals Window, ref3 is recognized as what I set the variable to, but it isn't recognized in the formula. Is the syntax correct? I've been able to run the code without the double quotes and it works, but it will ask me to update the value of ref3 by selecting the workbook and worksheet for every loop.

Jess