Renames a sheet in a workbook
static int WorkbookName( LPCTSTR oldname_text, LPCTSTR newname_text );
Oldname_text is the name of the sheet that you want to rename.
Newname_text is the new name of the sheet.
Zero if the function has been called successfully; non-zero if the function could not be called. See Error codes for a list of return values.
See the Microsoft Excel on-line Help for full details about this function.