Excel listing named range in a worksheet and get the value

Question

How to obtain a list of named range exist in a specific worksheet that start with particular string (for example all named range that start with total) and grab the value? I am trying to do Sub Total and Grand Total of accommodation cost based on the date. I will assign an unique name for each Sub Total based on the Date group. Then, I have a button that need to be clicked when it finishes to calculate the Grand Total based on the Named Range that I've assigned uniquely to each Sub Total.

Below is the code I wrote to do the Grand Total:

Sub btnTotal()

    Dim Total, LastRowNo As Long

    LastRowNo = ActiveSheet.UsedRange.Row + ActiveSheet.UsedRange.Rows.Count

    Total = 0

    For Each N In ActiveWorkbook.Names
        Total = Total + IntFlight.Range(N.Name).Value
    Next N

    IntFlight.Range("$P" & LastRowNo).Select
    Selection.NumberFormat = "$* #,##0.00;$* (#,##0.00);$* ""-""??;@"
    With Selection
        .Font.Bold = True
    End With

    ActiveCell.FormulaR1C1 = Total

End Sub

Note: the IntFlight from "Total = Total + IntFlight.Range(N.Name).Value" is the name of my worksheet.

The only problem with above code, it will looking all named range exist in the workbook. I just need to find named range exist in one particular worksheet, which start with given string and the row number (total26: means Sub Total from row 26) and then grab the value to be sum-ed as Grand Total.

Any ideas how to do this? Been spending 2 days to find the answer.

Thanks heaps in advance.

EDIT 1 (Solution Provided by Charles Williams with help from belisarius):

This is what I have done with the code from Charles Williams:

Option Explicit
Option Compare Text

Sub btnIntFlightsGrandTotal()

    Dim Total, LastRowNo As Long
    LastRowNo = FindLastRowNo("International Flights")

    Dim oNM As Name
    Dim oSht As Worksheet
    Dim strStartString As String

    strStartString = "IntFlightsTotal"
    Set oSht = Worksheets("International Flights")

    For Each oNM In ActiveWorkbook.Names
        If oNM.Name Like strStartString & "*" Then
            If IsNameRefertoSheet(oSht, oNM) Then
                Total = Total + Worksheets("International Flights").Range(oNM.Name).Value
            End If
        End If
    Next oNM

    IntFlights.Range("$P" & LastRowNo).Select
    Selection.NumberFormat = "$* #,##0.00;$* (#,##0.00);$* ""-""??;@"
    With Selection
        .Font.Bold = True
    End With

    ActiveCell.FormulaR1C1 = Total

End Sub

Function FindLastRowNo(SheetName As String) As Long

    Dim oSheet As Worksheet
    Set oSheet = Worksheets(SheetName)

    FindLastRowNo = oSheet.UsedRange.Row + oSheet.UsedRange.Rows.Count

End Function

Thank you all for your help. Now, I need to come up with my own version for this script.

Answer 1

Here is some code that checks if a Defined Name starts with a string and refers to a range within the used range of a given worksheet and workbook.

Option Explicit
Option Compare Text
Sub FindNames()
    Dim oNM As Name
    Dim oSht As Worksheet
    Dim strStartString As String

    strStartString = "Total"
    Set oSht = Worksheets("TestSheet")

    For Each oNM In ActiveWorkbook.Names
        If oNM.Name Like strStartString & "*" Then
            If IsNameRefertoSheet(oSht, oNM) Then

                MsgBox oNM.Name
            End If
        End If
    Next oNM
End Sub

Function IsNameRefertoSheet(oSht As Worksheet, oNM As Name) As Boolean
    Dim oSheetRange As Range

    IsNameRefertoSheet = False
    On Error GoTo GoExit

    If Not oSht Is Nothing Then
        If Range(oNM.Name).Parent.Name = oSht.Name And _
           Range(oNM.Name).Parent.Parent.Name = oSht.Parent.Name Then
            Set oSheetRange = oSht.Range("A1").Resize(oSht.UsedRange.Row + oSht.UsedRange.Rows.Count - 1, oSht.UsedRange.Column + oSht.UsedRange.Columns.Count - 1)
            If Not Intersect(Range(oNM.Name), oSheetRange) Is Nothing Then IsNameRefertoSheet = True
            Set oSheetRange = Nothing
        End If
    End If

    Exit Function
GoExit:
End Function