The code of JS20'07'11 is really incredible simple and direct. One suggestion that I would like to give is to put a exclamation mark in the conditions:
InStr(1, objName.RefersTo, sWsName+"!", vbTextCompare)
Because this will prevent adding a NamedRange in an incorrect Sheet. Eg: If the NamedRange refers to a Sheet named Plan11 and you have another Sheet named Plan1 the code can do some mess when add the ranges if you don't use the exclamation mark.
UPDATE
A correction: It's best to use a regular expression evaluate the name of the Sheet. A simple function that you can use is the following (adapted by http://blog.malcolmp.com/2010/regular-expressions-excel-add-in, enable Microsoft VBScript Regular Expressions 5.5):
Function xMatch(pattern As String, searchText As String, Optional matchIndex As Integer = 1, Optional ignoreCase As Boolean = True) As String
On Error Resume Next
Dim RegEx As New RegExp
RegEx.Global = True
RegEx.MultiLine = True
RegEx.pattern = pattern
RegEx.ignoreCase = ignoreCase
Dim matches As MatchCollection
Set matches = RegEx.Execute(searchText)
Dim i As Integer
i = 1
For Each Match In matches
If i = matchIndex Then
xMatch = Match.Value
End If
i = i + 1
Next
End Function
So, You can use something like that:
xMatch("'?" +sWsName + "'?" + "!", objName.RefersTo, 1) <> ""
instead of
InStr(1, objName.RefersTo, sWsName+"!", vbTextCompare)
This will cover Plan1 and 'Plan1' (when the range refers to more than one cell) variations
TIP: Avoid Sheet names with single quotes ('), :) .