How macro to change excel source file path - vba

Question

I'm Very New to Macro and VB. I recorded one macro in Word, below is some portion of the code.
ActiveDocument.MailMerge.OpenDataSource Name:= _
"Choosen/Folder/Path/file.xlsx", ConfirmConversions:= _
False, ReadOnly:=False, LinkToSource:=True, AddToRecentFiles:=False, _
PasswordDocument:="", PasswordTemplate:="", WritePasswordDocument:="", _
WritePasswordTemplate:="", Revert:=False, Format:=wdOpenFormatAuto, _
Connection:= _
"User ID=Admin;Data Source=Choosen/Folder/Path/file.xlsx;Mode=Read;Extended Properties=""HDR=YES;IMEX=1;"";Jet OLEDB:System database="""";Jet OLEDB:Registry Path="""";Jet OLEDB:Engine Type=35;Jet OLEDB:Database L" _
, SQLStatement:="SELECT * FROM `Sheet1$`", SQLStatement1:="", SubType:= _
wdMergeSubTypeAccess
How can I allow user to choose DataSource every time?
I tried the following:
Public Function ChooseFolder()
Dim fldr As FileDialog
Dim sItem As String
Set fldr = Application.FileDialog(msoFileDialogFilePicker)
With fldr
.Title = "Select a Folder"
.AllowMultiSelect = False
.InitialFileName = strPath
If .Show <> -1 Then GoTo NextCode
sItem = Replace(.SelectedItems(1), "\", "\\")
End With
NextCode:
ChooseFolder = sItem
Set fldr = Nothing
End Function
Sub .....
..
Dim fldr As String
fldr = ChooseFolder()
ActiveDocument.MailMerge.OpenDataSource Name:= _
fldr, ConfirmConversions:= _
....
End Sub
But have the following error:

Answer 1

There's a Word dialog box specifically for opening a mailmerge data source.
e.g. at its simplest,
Sub openmmds1()
Dialogs(WdWordDialog.wdDialogMailMergeOpenDataSource).Show
End Sub
although some people say the "correct" way to use these dialogs is as follows:
Sub openmmds2()
Dim dlg As Word.Dialog
Set dlg = Dialogs(WdWordDialog.wdDialogMailMergeOpenDataSource)
dlg.Show
Set dlg = Nothing
End Sub
and you may find that closing any existing data source first avoids some problems. In modern versions of Word on both Windows and Mac you should be able to do that this way:
ActiveDocument.MailMerge.DataSource.Close
but in older versions there is no .Close method and you have to remove all the MailMerge info using, e.g.
ActiveDocument.MailMerge.MainDocumentType = WdMailMergeMainDocType.wdNotAMergeDocument