Consider:
Function GetFolder() As String
Dim fldr As FileDialog
Dim sItem As String
Set fldr = Application.FileDialog(msoFileDialogFolderPicker)
With fldr
.Title = "Select a Folder"
.AllowMultiSelect = False
.InitialFileName = Application.DefaultFilePath
If .Show <> -1 Then GoTo NextCode
sItem = .SelectedItems(1)
End With
NextCode:
GetFolder = sItem
Set fldr = Nothing
End Function
This code was adapted from Ozgrid
and as jkf points out, from Mr Excel