Quickfixj 2.3 - NewOrderMultileg support for 4.2

Question

Using QuickFixJ 2.3..

We have requirement to support NewOrderMultileg for 4.2. Weare dealing with raw fix message. So I used parse method, which internally create the instance of NewOrderMultileg.

However, for 4.2 ,can't find such instance.

I tried by modifying the DD for FIX42.xml to include the message type, components and fields to work for Multileg.

Now, probably need to extend/implememt messagefactory.

Need to know better approach for the same.

Thanks in advance.