JCO.Function function =  getDefaultJCoConnection().getJCoFunction("Function_Module_Name");

JCO.ParameterList importParam = function.getImportParameterList();
importParam.setValue("Field_Value",  "Field_Name");
(or)
function.getImportParameterList().getField("Field_Name").setValue("Field_Value");

JCO.Structure structure =  importParam.getStructure("Structure_Name");
structure.setValue("Field_Value", "Field_Name");
(or)
function.getImportParameterList().getStructure("Structure_Name").setValue("Field_Value", "Field_Name");

JCO.Table table = function.getTableParameterList().getTable("Table_Name");
table.appendRow();

JCoHelper.setValue(table,"Field_Value", "Field_Name");
(or)
table.setValue("Field_Value", "Field_Name");

JCO.ParameterList exportParams = function.getExportParameterList();

String  returnCode  = exportParams.getString("Field_Name");
(or)
String returnCode= function.getExportParameterList().getString("Field_Name");

Table resultTable = func.getTableParameterList().getTable("Table_Name");


for (int i = 0; i < resultTable.getNumRows(); i++, resultTable.nextRow()){
 result = resultTable.getString("Field_Name");
}

(or)

for (int i = 0; i < resultTable.getNumRows(); i++){
 resultTable.setRow( i );
}

result = resultTable.getString("Field_Name");