If a named Excel cell/range is located on a worksheet whose name contains a hyphen (-), the range address cannot be resolved correctly. Instead, the Range.Start property bombs out with an exception (invalid row number -1 or similar). I.e. this will not work: "ASI-Sheet!$B$2", whereas this will: "ASISheet!$B$2", despite the fact that both names are valid in Excel. I haven't tried other char combos (blanks and/or underscores), but please fix at your earliest convenience.