Export-File-Format
This property specifies the default file format in which List-Box data must be exported 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 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 list-box with a XLSX document associated for the export feature
| ...   03 screen-1-lb-1 List-Box      line 5.7      column 3.1      size 34.6 cells       lines 15.5 cells       id 1      export-file-format "xlsx"      export-file-name "output.xlsx"      event procedure screen-1-lb-1-evt-proc      . |