Link to external workbook based on another cell

Question

I'm working on dynamic external workbook data referencing in Excel, can someone please help considering the following:

In my workbook in A2 I have = 'C:\\'&A1&' Reports\\[1.xls]Sheet1'!C1)

A1 will contain either

Folder A
Folder B

So depending on the value in A1, I want to point to either

D:\\Folder A Reports\\1.xls
D:\\Folder B Reports\\1.xls

How can I achieve this?

Thank you!

Answer 1

Indirect is the function you need:

=INDIRECT("'C:\" & A1 & " Reports\[1.xls]Sheet1'!C1")

The problem I see though is it won't resolve if the sheet is not open.

Answer 2

As INDIRECT doesn't work on closed books and it is expensive to have to open them then the normal soutions for this are to

1. create a dirty link with VBA.
2. Use Indirect.Ext from the Morefunc addin.
3. My preferred approach, use XLM which Harlan Grove has improved in his pull function below.

To use for your purpose:

=pull("'C:\\"&A1&"\\"&"[1.xls]Sheet1'!C1")

From https://numbermonger.wordpress.com/2012/02/11/excel-pull-function-creating-dynamic-links-to-closed-workbooks/

Pull function

Function pull(xref As String) As Variant
'inspired by Bob Phillips and Laurent Longre
'but written by Harlan Grove
'-----------------------------------------------------------------
'Copyright (c) 2003 Harlan Grove.
'
'This code is free software; you can redistribute it and/or modify
'it under the terms of the GNU General Public License as published
'by the Free Software Foundation; either version 2 of the License,
'or (at your option) any later version.
'-----------------------------------------------------------------
'2004-05-30
'still more fixes, this time to address apparent differences between
'XL8/97 and later versions. Specifically, fixed the InStrRev call,
'which is fubar in later versions and was using my own hacked version
'under XL8/97 which was using the wrong argument syntax. Also either
'XL8/97 didn't choke on CStr(pull) called when pull referred to an
'array while later versions do, or I never tested the 2004-03-25 fix
'against multiple cell references.
'-----------------------------------------------------------------

'2004-05-28
'fixed the previous fix - replaced all instances of 'expr' with 'xref'
'also now checking for initial single quote in xref, and if found
'advancing past it to get the full pathname [dumb, really dumb!]
'-----------------------------------------------------------------
'2004-03-25
'revised to check if filename in xref exists - if it does, proceed;
'otherwise, return a #REF! error immediately - this avoids Excel
'displaying dialogs when the referenced file doesn't exist
'-----------------------------------------------------------------
Dim xlapp As Object, xlwb As Workbook
Dim b As String, r As Range, C As Range, n As Long
'** begin 2004-05-30 changes **

'** begin 2004-05-28 changes **
'** begin 2004-03-25 changes **
n = InStrRev(xref, "\")
If n > 0 Then
If Mid(xref, n, 2) = "\[" Then
b = Left(xref, n)
n = InStr(n + 2, xref, "]") - n - 2
If n > 0 Then b = b & Mid(xref, Len(b) + 2, n)
Else
n = InStrRev(Len(xref), xref, "!")
If n > 0 Then b = Left(xref, n - 1)
End If

'** key 2004-05-28 addition **
If Left(b, 1) = "'" Then b = Mid(b, 2)
On Error Resume Next
If n > 0 Then If Dir(b) = "" Then n = 0
Err.Clear
On Error GoTo 0
End If

If n <= 0 Then
pull = CVErr(xlErrRef)
Exit Function
End If
'** end 2004-03-25 changes **
'** end 2004-05-28 changes **
pull = Evaluate(xref)

'** key 2004-05-30 addition **
If IsArray(pull) Then Exit Function
'** end 2004-05-30 changes **

If CStr(pull) = CStr(CVErr(xlErrRef)) Then
On Error GoTo CleanUp 'immediate clean-up at this point

Set xlapp = CreateObject("Excel.Application")
Set xlwb = xlapp.Workbooks.Add 'needed by .ExecuteExcel4Macro

On Error Resume Next 'now clean-up can wait

n = InStr(InStr(1, xref, "]") + 1, xref, "!")
b = Mid(xref, 1, n)

Set r = xlwb.Sheets(1).Range(Mid(xref, n + 1))

If r Is Nothing Then
pull = xlapp.ExecuteExcel4Macro(xref)

Else
For Each C In r
C.Value = xlapp.ExecuteExcel4Macro(b & C.Address(1, 1, xlR1C1))
Next C

pull = r.Value

End If

CleanUp:
If Not xlwb Is Nothing Then xlwb.Close 0
If Not xlapp Is Nothing Then xlapp.Quit
Set xlapp = Nothing

End If

End Function

Answer 3

External references to closed files in Excel formulas can't be dynamic, so maybe something like this:

=IF(A1="Folder A", 'C:\Folder A Reports\[1.xls]Sheet1'!C1,
                   'C:\Folder B Reports\[1.xls]Sheet1'!C1)