HSSFSheet sheet = wb.getSheetAt(0);
/**
* register the two test UDFs in a UDF finder, to be passed to the evaluator
*/
UDFFinder udff1 = new DefaultUDFFinder(new String[] { "myFunc", },
new FreeRefFunction[] { new MyFunc(), });
UDFFinder udff2 = new DefaultUDFFinder(new String[] { "myFunc2", },
new FreeRefFunction[] { new MyFunc2(), });
UDFFinder udff = new AggregatingUDFFinder(udff1, udff2);
HSSFRow row = sheet.getRow(0);
HSSFCell myFuncCell = row.getCell(1); // =myFunc("_")