Range Names in Excel Charts

[forest8]

I've created a series of Range names which I would like to use in a chart.
But I get the following error message when I try to use the range names in
the Values box:

"Your formula contains an invalid external reference to a worksheet.
Verity that the path, workbook, and range name or cell reference are correct
and try again."

Thanks

 

[Peter T]

='BookName.xls'!theName

If the name is a Worksheet level name (Local), replace the file name with
the sheet name.

The apostrophes aren't necessary above but might be if the file name
contains say a space or some other characters.

Regards,
Peter T