How to sorting an excell when i export with dotnets

First set secondary key in NAV dataset to set your sorting.
Then use this:

WITH MyRecord DO BEGIN
RESET;
SETCURRENTKEY(Key1,Key2,Key3...);
IF ISEMPTY THEN
ERROR('No Records');
FIND('+');
REPEAT
//Add to Excel Buffer

UNTIL NEXT(-1) = 0;
END;