VS 2008 Running an Excel macro from VB2008

I have written a program that needs to import data from an Excel spreadsheet. To do so I have created a Macro in Excel called "LoadAndFormatRates" that removes several unwanted lines and then some spaces between words so that they are single words. I have written the following code to run the macro from VB2008:

Imports System.Data.Odbc
Imports Excel = Microsoft.Office.Interop.Excel

Public Class Form1

Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
Dim cn As OdbcConnection = New OdbcConnection
cn.ConnectionString = "Driver={Microsoft Excel Driver (*.xls)};Dbq=C:\FXEXRATESTest.xls;Uid=Admin;Pwd=;"
cn.Open()

'Define Xcel objects
Dim xlApp As New Excel.Application
Dim xlWorkBook As Excel.Workbook

'Start Excel and open the workbook

xlWorkBook = xlApp.Workbooks.Open("C:\FXEXRATESTest.xls")

'Run the macro
xlApp.Run("LoadAndFormatRates")
'Clean-up: Close the Workbook and quit Excel
xlWorkBook.Close(False)
'Quit the Excel Application
xlApp.Quit()
'Clean up
releaseObject(xlApp)
releaseObject(xlWorkBook)
End Sub
Private Sub releaseObject(ByVal obj As Object)
Try
System.Runtime.InteropServices.Marshal.ReleaseComObject(obj)
obj = Nothing
Catch ex As Exception
obj = Nothing
Finally
GC.Collect()
End Try
End Sub
End Class

but as soon as it reaches the RUN(LoadAndFormatRates) it throws up the following message:

Cannot run the macro 'LoadAndFormatRates'. The macro may not be available in this workbook or all macros may be disabled.

I have searched various Forums to find an answer for this error but without success.

Can anyone throw some light upon the matter?

Kind regards