Modifying workbook properties isn't what writetable does--it just writes to a given sheet, creating one of that name if it doesn't exist. That's the same behavior in xlswrite
There is no builtin ML function to do such other manipulations of a workbook; you'll have to do that via COM.
Alternatively, build a template workbook that you duplicate for new workbooks with the desired sheet name(s) and write to (the new copy of) it instead.
