// Generate the new <w:num
long newNumId = instanceListDefinitions.size() + 1;
org.docx4j.wml.ObjectFactory factory = Context.getWmlObjectFactory();
Num newNum = factory.createNumberingNum();
newNum.setNumId( BigInteger.valueOf(newNumId) );
AbstractNumId abstractNumId = factory.createNumberingNumAbstractNumId();
abstractNumId.setVal(abstractNumIdVal);
newNum.setAbstractNumId(abstractNumId);
LvlOverride lvlOverride = factory.createNumberingNumLvlOverride();
lvlOverride.setIlvl(BigInteger.valueOf(ilvl));
newNum.getLvlOverride().add(lvlOverride);
StartOverride start = factory.createNumberingNumLvlOverrideStartOverride();
start.setVal(BigInteger.valueOf(val));
lvlOverride.setStartOverride(start);