Export-File-Format
This property specifies the default file format in which Grid data must be exported when the ‘Export’ item is selected from the context menu (see 
Heading-Menu-Popup) or when the 
Action property is set to 
action-export.
Possible values (case insensitive) are:
Value  | Meaning  | 
|---|
XLSX  | Excel Workbook  | 
XLS  | Excel 97- Excel 2003 Workbook  | 
If the property is not set, then "XLS" is assumed.
The cells in the spreadsheet are set as Numeric only for columns for which the 
Data-Types property is set to "9". Any other value of the 
Data-Types property generates Text cells in the spreadsheet.
The cell format in the generated spreadsheet is set according to the following rules:
•	If the cell value contains the decimal and the group separator, the format is set to '#,##0.' plus a '0' for each digit after the decimal separator.
•	If the cell value contains the decimal separator but not the group separator, the format is set to '0.' plus a '0' for each digit after the decimal separator.
•	If the cell value contains the group separator but not the decimal separator, the format is set to '#,###'.
•	If the cell value contains neither decimal nor group separator, no cell format is set.
Example - Define a grid with a XLSX file associated for the export feature
...   03 screen-1-gr-1 Grid      line 5.7      column 3.1      size 34.6 cells       lines 15.5 cells       id 1      export-file-name "output.xlsx"      export-file-format "xlsx"      event procedure screen-1-gr-1-evt-proc      no-box      column-headings      row-dividers 1      end-color 9      heading-font Default-Font      cursor-frame-width 3      num-rows 5      .  |