Select a file with the Microsoft file dialog. Requires reference to Microsoft Object Library x.x, where x.x is the version number. title, start and filter correspond to Dialog Box title, the start directory and extension filters to apply.

PickFile.vb

Function PickFile(title As String, start As String, filter As String) As String

    Dim dlg As FileDialog
    Set dlg = Application.FileDialog(msoFileDialogFilePicker)
    
    With dlg
        .title = title
        .InitialFileName = start
        .AllowMultiSelect = False
        .Filters.Clear
        .Filters.Add filter, "*." & filter & "*", 1
        If .Show = True Then
            PickFile = .SelectedItems(1)
        Else
            Exit Function
        End If
    End With
        
End Function