This property is applicable for export operations only.
The style gets all the properties defined in the base style,
and can override or augment them by setting its own properties.
Cell value format, defined using Excel format syntax.
The description of Excel format syntax can be found
here.
You may use the toXlsxNumberFormat and toXlsxDateFormat
static functions of the Workbook class to convert from .Net
(Globalize) format to Excel format.
Represents the Workbook Object Model style definition used to style Excel cells, columns and rows.