Ok,
you would need to replace the following line:
DoCmd.OutputTo acQuery, "qryFilterPostCodes", "MicrosoftExcel(*.xls)", "c:\Temp\PostCodes.xls", True, ""
With the following:
DoCmd.OutputTo acQuery, "qryFilterPostCodes", "MicrosoftExcel(*.xls)", "C:\Documents and Settings\All...